Angleman syndrome antisense treatment

ABSTRACT

Disclosed herein are antisense oligonucleotides that are capable of inducing expression of ubiquitin-protein ligase E3A (UBE3A) from the paternal allele in animal or human neurons. The oligonucleotides target the suppressor of the UBE3A paternal allele by hybridization to SNHG14 long non-coding RNA at the 5′-end of UBE3A-AS, which is downstream of SNORD115-45 snoRNA. Also disclosed are pharmaceutical compositions and methods for treatment of Angelman syndrome.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of copending application Ser. No.17/523,456, filed Nov. 10, 2021, which is a continuation of copendingapplication Ser. No. 16/767,916, filed May 28, 2020, is a National Stageof International Application No. PCT/US2018/063416, filed Nov. 30, 2018,which claims benefit of U.S. Provisional Application No. 62/593,431,filed Dec. 1, 2017, and Application Ser. No. 62/676,034, filed May 24,2018, which are hereby incorporated herein by reference in theirentirety.

SEQUENCE LISTING

This application contains a sequence listing filed in ST.26 formatentitled “922001-1022” created on Dec. 9, 2022. The content of thesequence listing is incorporated herein in its entirety.

BACKGROUND

Angelman syndrome (AS) is a neurodevelopmental disorder that isassociated with severe cognitive and motor deficits, epilepsy,sleep-disorder, and an atypical ‘happy’ disposition. Individuals with ASare often diagnosed at 2-3 years of age and have a normal life-span.They require assisted living and medical care throughout their lives.There are currently few treatment options for individuals with AS, mostof which involve anti-epileptic medications to treat seizures.

Angelman syndrome is caused by mutations that affect the expression orfunction of the maternally inherited ubiquitin-protein ligase E3A(UBE3A) gene. Unlike most genes, UBE3A is subject to genomic imprinting,which is a rare, naturally occurring phenomenon that turns-off oneallele of a gene while leaving the other allele on. In neurons of thecentral nervous system (CNS), the paternal UBE3A allele is off, whereasin all other cell types of the body, both alleles of UBE3A are on.Because of this, AS is always caused by mutations that affect thematernally inherited UBE3A allele.

The paternal UBE3A allele is turned-off by the UBE3A antisensetranscript (UBE3A-AS), which is a component of a long RNA transcriptthat expresses several protein coding and noncoding transcripts.UBE3A-AS is expressed from the paternal allele and only in neurons ofthe CNS and is both sufficient and necessary to turn-off expression ofthe paternal UBE3A allele. It's unclear why UBE3A is imprinted inneurons, but it creates a unique opportunity to treat individuals withAS, because there is a functional, albeit inactive, copy of UBE3A on thepaternal chromosome. Studies to date indicate that turning on thepaternal UBE3A allele is a viable therapy to treat AS.

SUMMARY

Disclosed herein is a region in the 5′-end of UBE3A-AS transcript thatis important for its stability. Based on these findings, antisenseoligonucleotides (ASOs) were designed to target this region in order toterminate transcription of UBE3A-AS and reactivate expression of thepaternal UBE3A allele. These ASOs targeting the 5′-end of UBE3A-AS arecapable of stopping transcription of UBE3A-AS and turning on thepaternal UBE3A allele. SNHG14 is a polycistronic transcript that encodesseveral different RNAs, including UBE3A-AS.

Accordingly, disclosed herein are ASOs containing a contiguousnucleotide sequence of 10 to 30 nucleotides (i.e., 10, 11, 12, 13, 14,15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30) inlength with at least 98% (i.e. 98%, 99%, or 100%) complementarity totarget exons between the 3′-end of the SNORD115 and the 5′-end ofSNORD109B, which is thought to represent the 5′-end of the UBE3Aantisense transcript (UBE3A-AS). In particular the target exons can bein the 5′-end of UBE3A-AS, corresponding to position 25,511,577 to25,516,681 on human chromosome 15 human genome assembly hg19. In someembodiments, the target nucleic acid is one of five exons located in the5′-end of UBE3A-AS, which can correspond to positions 25,511,577 to25,511,761 (exon 1), 25,512,059 to 25,512,191 (exon 2), 25,513,476 to25,513,600 (exon 3), 25,514,752 to 25,514,880 (exon 4), and 25,516,565to 25,516,681 (exon 5). Therefore, the target nucleic acid can be acontiguous nucleic acid sequence of 10 to 30 nucleotides within SEQ IDNO:1, 2, 3, 4, or 5.

In some embodiments, the target sequence is an exonic boundary involving

UBE3A-AS exons 1-5, UBE3A-AS exon 5 and SNORD109B exon 1, and/orSNORD109B exons 1-2.

Methods and strategies for designing ASOs are known in the art. In someembodiments, the ASO is designed to target sequences that are conservedamong human subjects. In some embodiments, the ASO is designed to targetsequences that are conserved among primate subjects.

The oligonucleotide can be an antisense oligonucleotide (i.e., as willbe understood by those of ordinary skill in the art—antisense to itstarget nucleic acid), e.g., with a gapmer design. The disclosedoligonucleotide is capable of inducing paternal UBE3A expression in aneuron by degradation, reduction, or removal of the UBE3A-AS transcript.It does this by targeting the 5′-end of UBE3A-AS at a site upstream ofSNORD109B snoRNA. Examples of ASO designed to target exons 1-5 areprovided in Tables 1, 2, 3, 4, or 5. For example, in some embodiments,the ASO comprises the nucleic acid sequence SEQ ID NO: 6, 7, 8, 9, 10,or 11.

The disclosed ASOs can also have one or more modifications to improvestability, solubility, activity, cellular distribution, and/or cellularuptake. For example, the disclosed ASO can contain one or moresugar-modified nucleosides and/or modified internucleoside linkages. Forexample, in some embodiments, the oligonucleotide comprises one or moreinternucleoside linkages modified from the natural phosphodiester to alinkage that is for example more resistant to nuclease attack. In someembodiments, the ASO contains one or more modified nucleobases thatdiffer from naturally occurring nucleobases, but are functional duringnucleic acid hybridization.

In some embodiments, the ASO is a DNA oligonucleotide. In someembodiments, the ASO is an RNA oligonucleotide. In still otherembodiments, the ASO contains both deoxynucleotides and ribonucleotides.For example, the ASO can be a gapmer, headmer, or tailmeroligonucleotide. In some embodiments, the central block of a gapmer isflanked by blocks of modified ribonucleotides that protect the internalblock from nuclease degradation. For example, the ASO can contain astretch of 7, 8, 9, 10, or more natural DNA monomers to activate RNase Hcleavage of the target RNA, along with 3, 4, or 5 modifiedribonucleotide monomers at the 3′- and 5′-ends for protection againstexonucleases. In some cases, the modified ribonucleotides are2′-O-Methyl (OMe) RNA nucleotides, 2′-O-methoxyethyl (MOE)-modifiednucleotides, or 2′-Locked Nucleic Acids (LNAs). Examples of gapmer ASOsare provided Tables 7, 11, and 17. Therefore, in some embodiments, thedisclosed ASO has a nucleic acid sequence selected from SEQ ID NOs:362to 392.

Also disclosed are pharmaceutical compositions comprising one or more ofthe ASOs disclosed herein and pharmaceutically acceptable diluents,carriers, salts and/or adjuvants.

Also disclosed are methods for in vivo or in vitro induction of UBE3Aexpression in a target cell where expression of paternal UBE3A issuppressed, by administering one or more of the disclosed ASOs orcomposition disclosed herein in an effective amount to said cell.

Also disclosed are methods for treating or preventing a disease,disorder or dysfunction associated with in vivo activity of UBE3Acomprising administering a therapeutically or prophylactically effectiveamount of one or more of the disclosed ASOs to a subject suffering fromor susceptible to the disease, disorder or dysfunction, such as Angelmansyndrome.

The details of one or more embodiments of the invention are set forth inthe accompanying drawings and the description below. Other features,objects, and advantages of the invention will be apparent from thedescription and drawings, and from the claims. For example, thoseskilled in the art, reading the specification will appreciate that thepresent disclosure demonstrates usefulness of certain sequences asdescribed herein to impact expression of UBE3A, and furthermore teachesusefulness of oligonucleotide formats that are, or target (e.g., arecomplementary to), such sequences. Those skilled in the art willappreciate that the present disclosure is not limited to any particularmechanism of action—provided oligonucleotides may be useful regardlessof whether they act via an antisense mechanism, for example, involvingRNase H activity, and other therapeutic formats (e.g., siRNA, shRNA,nuclease gRNA, etc.) of oligonucleotides that are or target suchsequences are also provided. Analogously, those skilled in the art willappreciate that the present disclosure, by defining useful sequences asdescribed herein, also describes a variety of formats for such sequences(e.g., as part of a nucleic acid vector such as a vector from which theymay be expressed (e.g., in vivo, in vitro, or both, etc.). Thus, thoseskilled in the art, reading the present disclosure, will appreciate thatreference to “ASOs” herein is exemplary, and appropriate nucleic acids(e.g., oligonucleotides) may be utilized regardless of mechanism ofaction; those skilled in the art are aware of extensive literatureregarding appropriate format and structure of nucleic acids (e.g.,oligonucleotides) that operate via any of a variety of mechanisms (e.g.,siRNA, shRNA, nuclease gRNA, etc.). In some embodiments, providednucleic acids incorporate format and/or structural features known in theart to be useful in one or more mechanistic contexts (e.g., involvingRNase H, RISC, a nucleic-acid-directed nuclease such as a Cas, etc.).

DESCRIPTION OF DRAWINGS

FIGS. 1A to 1D illustrate the Prader-Willi/Angelman syndrome (PWS/AS)imprinted region in human and mouse. FIG. 1A shows RefSeq annotation ofhuman PWS/AS imprinted region. FIG. 1B shows RefSeq annotation of PWS/ASimprinted orthologous region in mouse. FIG. 1C shows UBE3A-AS and 3′-endof UBE3A. FIG. 1D shows chain alignment showing orthologous regionsbetween human, macaque (Cynomolgus macaque), pig, elephant, mouse, andrat. The target region is conserved among non-human primates but notrodents. FIG. 1D also shows genomic evolutionary rate profiling (GERP)plot of region. Positive values represent evolutionary constraint atspecific DNA bases.

FIGS. 2A to 2E show an analysis of ASOs targeting mouse Ube3a-AS. FIG.2A is a schematic of mouse Ube3a-AS transcript and approximate locationof mouse-specific ASOs. Boxes and lines represent exons and introns,respectively. Arrow represents direction of transcription. FIG. 2B is aschematic of Ube3aYFP reporter allele used to measure paternal Ube3aprotein levels. The Ube3aYFP mouse model was generated by targeting theyellow fluorescent protein (YFP) to the 3′-end of the endogenous Ube3alocus. Expression of Ube3a-AS inhibits transcription of the paternalUbe3aYFP allele, and loss of Ube3a-AS reactivates paternal Ube3aYFPexpression, which can be detected by immunofluorescence imaging using ananti-YFP antibody. FIG. 2C is a schematic of experimental timeline toexamine ASOs in mouse primary hippocampal neurons. Mouse primaryhippocampal neurons were generated from newborn mice with a paternallyinherited Ube3aYFP allele (0 DIV) and treated after 7 days in vitro (7DIV). Three days post-treatment (10 DIV), Ube3aYFP protein levels weremeasured in individual cells. FIG. 2D contains immunofluorescent imagesshowing paternal Ube3aYFP protein in primary neurons treated withvehicle (veh), a negative control ASO (ASO-C), Topotecan (Topo), ASO-B,and ASO 1.1. FIG. 2E shows mean paternal Ube3aYFP intensity levels inindividual neuronal cells treated with vehicle (veh, 1% DMSO; n=3),control ASO (ASO-C, 15 μM; n=3), Topotecan (Topo, 0.3 μM; n=3), ASO-B(1, 5, 15 μM; n=3), ASO-1.1 (1, 5, 15 μM), ASO-1.2 (1, 5, 15 μM), andASO 3.1 (1, 5, 15 μM). Abbreviations: YFP, yellow fluorescent protein;Tx, treatment; DIV, days in vitro; n.s., not significant. Error barsrepresent standard error of mean.

FIGS. 3A to 3D show analysis of ASOs targeting human UBE3A-AS. FIG. 3Ais a schematic showing of human UBE3A-AS and approximate location ofhuman-specific ASOs (ASOs 1-6). ASO-7 is located in an intron ofUBE3A-AS. Boxes and lines represent exons and introns, respectively.FIG. 3B is a schematic of experimental timeline to examine ASOs in humanGABAergic induced pluripotent stem cell (iPSC) derived neurons from akaryotypically normal individual. Human iPSC-derived neurons weretreated after 14 DIV and then processed for RNA isolation at 20 DIV.FIGS. 3C and 3D show relative steady state RNA levels (normalized toASO-C) of UBE3A-AS (FIG. 3C) and UBE3A (FIG. 3D) in iPSC-derived neuronstreated with control ASO (ASO-C, 10 μM), and ASOs 1-7 (10 μM), andTopotecan (Topo, 1 μM). Abbreviations: Tx, treatment; DIV, days invitro. Error bars represent standard error of mean.

FIGS. 4A to 4I show analysis of human ASO-4 and Topotecan in GABAergiciPSC-derived neurons. FIGS. 4A to 4F show relative expression(normalized to 1 nM) of UBE3A-AS (FIG. 4A), SNORD116 (FIG. 4B), IPW(FIG. 4C), SNORD115 (FIG. 4D), SNORD109A/B (FIG. 4E), and UBE3A (FIG.4F) steady state RNA levels in iPSC-derived neurons treated with a10-point % log dose curve of ASO-4 and Topotecan (1 nM, 3 nM, 10 nM, 30nM, 100 nM, 300 nM, 1 μM, 3 μM, 10 μM, and 30 μM). FIG. 4G is aschematic of experimental timeline to examine ASO-4 in GABAergiciPSC-derived neurons treated at 59 DIV. FIG. 4H to 4I shows relativeexpression (normalized to ASO-C) of UBE3A-AS (FIG. 4H) and UBE3A (FIG.4I) steady state RNA levels in iPSC-derived neurons treated with ASO-C(10 μM) and ASO-4 (1, 5, and 10 μM). Abbreviations: Tx, treatment. Errorbars represent standard error of mean.

FIGS. 5A to 5F shows analysis of optimized ASOs in human GABAergic andglutamatergic iPSC-derived neurons. FIG. 5A is a schematic ofexperimental timeline to examine optimized ASOs in GABAergiciPSC-derived neurons. FIG. 5B shows relative expression of (normalizedto water control) of UBE3A-AS steady state RNA levels in iPSC-derivedneurons treated with a 5-point % log dose curve (30 nM, 100 nM, 300 nM,1 μM, 3 μM; n=6) of ASO-3.1, ASO-3.2, ASO-4.1, ASO-4.2, ASO-4.3,ASO-4.4, ASO-6.1, ASO-4.1, and ASO-4.S. ASO-4.1 and ASO-4.S representASO-4 manufactured by two companies (ASO-4.1, Integrated DNATechnologies; ASO-4.S,

Sigma-Aldrich). FIG. 5C is a schematic of experimental timeline toexamine ASO-4 and ASO-6.1 in GABAergic iPSC-derived neurons. FIG. 5Dshows relative expression of (normalized to 1 nM) of UBE3A-AS and UBE3Asteady state RNA levels in iPSC-derived neurons treated with a 10-point% log dose curve (1 nM, 3 nM, 10 nM, 30 nM, 100 nM, 300 nM, 1 μM, 3 μM,10 μM, and 30 μM; n=3) of ASO-4 (ASO-4.1 and ASO-4.S) and ASO-6.1. FIG.5E is a schematic of experimental timeline to examine ASO-4 and ASO-6.1in glutamatergic iPSC-derived neurons. FIG. 5F shows relative expressionof (normalized to water control) of UBE3A-AS and UBE3A steady state RNAlevels in iPSC-derived neurons treated with a 10-point % log dose curve(1 nM, 3 nM, 10 nM, 30 nM, 100 nM, 300 nM, 1 μM, 3 μM, 10 μM, and 30 μM;n=3) of ASO-4 (ASO-4.1 and ASO-4.S) and ASO-6.1. Error bars representstandard error of mean.

FIG. 6A to 6D show identification of ASO target region in mouse PWS/ASimprinted region. FIG. 6A shows RefSeq annotation of the orthologousPWS/AS imprinted region on mouse chromosome 7C. FIG. 6B illustrates atranscript assembly generated from RNA-sequencing (RNA-seq) data frommouse brain. FIG. 6C shows ASO target region showing Snord115 snoRNAsretained in exons of the Snord115 host-gene transcript/5′-end ofUbe3a-AS. Aligned RNA-seq reads are depicted below assembledtranscripts. Exons and introns are depicted by boxes and lines,respectively. FIG. 6D is a sequence alignment of snoRNAs in retainedexons

-   -   Snord115_ENSMUST00000101836 (SEQ ID NO:490),    -   Snord115_ENSMUST00000101936 (SEQ ID NO:491),    -   Snord115_ENSMUST00000104493 (SEQ ID NO:492),    -   Snord115_ENSMUST00000082443 (SEQ ID NO:493), and    -   Snord115_ENSMUST00000104427 (SEQ ID NO:494), showing retained        snoRNAs have a degenerate C Box, which is required for        functional snoRNA formation. The consensus sequence is SEQ ID        NO:604.

FIGS. 7A to 7G show identification of ASO target region in human PWS/ASimprinted region. FIG. 7A shows RefSeq annotation ofPrader-Willi/Angelman syndrome (PWS/AS) imprinted region. FIG. 7B showsRNA-seq assembly of the human PWS polycistronic transcript. FIG. 7Cshows SNORD115-45 is retained in an exon at the 3′-end of the SNORD115host-gene transcript/5′-end of UBE3A-AS. Aligned RNA-seq reads generatedfrom adult human brain showing L1 LINE is transcribed. FIG. 7D showsRefSeq annotation of 3′-end of SNORD115 cluster (SNORD115-39-48 andSNORD109B). FIG. 7E shows location of L1 LINE element betweenSNORD115-44 and SNORD115-45. FIG. 7F shows chain alignment of placentalmammals representing major clades showing conservation at SNORD115-45-48region, albeit reduced in rodents. FIG. 7G shows sequence alignment ofsnoRNAs in target region to SNORD115-44 (functional snoRNA) (SEQ IDNO:495), SNORD115-48 (SEQ ID NO:496), SNORD115-45 (SEQ ID NO:497),SNORD115-46 (SEQ ID NO:498), and SNORD115-47 (SEQ ID NO:499), showingSNORD115-45 (retained), SNORD115-46 (partially retained), andSNORD116-47 have degenerate C Box, which is required for functionalsnoRNA formation. The consensus sequence is SEQ ID NO:605.

FIGS. 8A to 8C show pharmacodynamic analysis of candidate ASOs. FIG. 8Ashows fitted dose response curves of normalized UBE3A-AS steady stateRNA levels in GABAergic iPSC-derived neurons treated with a 10-point ½log dose curve (1 nM, 3 nM, 10 nM, 30 nM, 100 nM, 300 nM, 1 μM, 3 μM, 10μM, and 30 μM; n=2) of ASO-4 and ASO-6.1 with different backbone and RNAmodification designs. Dose response curves fitted using a 4-parameterlogistic regression model (Hill). Graphs represent fitted models andstandard error. The Y axis represents relative UBE3A-AS RNA levels and Xaxis represents log molar (M) concentrations of ASO. FIGS. 8B and 8C arehierarchical clustering dendrogram and constellation plots of fitteddose response curves showing relationship between candidate ASOs andgrouping into 3 clusters.

FIG. 9 shows pharmacodynamic analysis of ASO-6.1.PO-1.O and ASO-4.4.PS.L in Angelman syndrome iPSC-derived neurons. 4-Parameterlogistic regression model (Hill) of normalized UBE3A-AS steady state RNAlevels in Angelman syndrome iPSC-derived neurons treated with a 10-point½ log dose curve (1 nM, 3 nM, 10 nM, 30 nM, 100 nM, 300 nM, 1 μM, 3 μM,10 μM, and 30 μM; n=3) of ASO-6.1.PO-1.O and ASO-4.4.PS.L.

FIG. 10 shows expression analysis of RNAs encoded by the PWSpolycistronic transcript in Angelman syndrome iPSC neurons treated withASO-6.1-PO-1.O and ASO-4.4.PS.L. Shown are normalized steady state RNAlevels of SNURF, SNRPN, SNHG116, SNORD116 snoRNAs, IPW, SNHG115,SNORD115 snoRNAs, UBE3A-AS, and UBE3A in AS iPSC-derived neurons treatedwith vehicle (1% H₂O; n=3), ASO-6.1.PO-1.O (30 μM; n=3), andASO-4.4.PS.L (30 μM; n=3).

Data represents mean percentage of RNA relative to vehicle. Error barsrepresent standard error of mean. Asterisk (*) denotes statisticallysignificant differences (p<0.05) using one-way ANOVA with Dunnett'smultiple comparison test relative to vehicle.

FIG. 11 shows pharmacodynamic analysis of ASO-6.1.PO-1.O andASO-4.4.PS.L in Cynomolgus macaque. Shown are steady state RNA levels ofUBE3A-AS in macaque CNS regions treated with vehicle (0.9% saline; n=5),ASO-6.1.PO-1.O (10 mg; n=3), and ASO-4.4.PS.L (10 mg; n=3). Datarepresents means percentage of UBE3A-AS RNA relative to vehicle. Errorbars represent standard error of mean. Asterisk (*) denotesstatistically significant differences (p<0.05) using one-way ANOVA withDunnett's multiple comparison test relative to vehicle.

DETAILED DESCRIPTION

The UBE3A-AS/Ube3a-AS transcript, otherwise known as ubiquitin-proteinligase E3A antisense transcript and UBE3A-AS/Ube3a-AS, is the name forthe transcript generated by transcription of the UBE3A-AS transcript,which is on the antisense DNA strand relative to the UBE3A gene. Notethat gene names with all caps indicate human genes (e.g. UBE3A) and genenames with only the first letter capped indicate mouse genes (e.g.Ube3a). The UBE3A-AS transcript is transcribed as part of a largepolycistronic transcription unit that encodes SNURF-SNRPN, a cluster oforphan C/D box small nucleolar RNAs (SNORDs), and severaluncharacterized long noncoding RNAs. In both mouse and human, theUBE3A/Ube3a gene is imprinted in neurons of the central nervous system,where it is expressed only from the maternal allele. TheUBE3A-AS/Ube3a-AS transcript is both necessary and sufficient to silencetranscription of the paternal UBE3A/Ube3a allele, and inhibition ofUBE3A-AS/Ube3a-AS reactivates transcription of the paternal UBE3A/Ube3aallele. Mutations affecting the function or expression of the maternallyinherited UBE3A allele cause Angelman syndrome (AS). In AS, the paternalallele is functional but epigenetically silenced. If unsilenced in ASpatients, the paternal UBE3A allele could be a source of functionalUBE3A in neurons.

The polycistronic transcription unit (hereafter referred to as the PTU)encoding UBE3A-AS is about 450,000 base-pairs long. Transcription of thePTU starts at upstream exons (U-exons) in the SNURF-SNRPN locus andstops towards the 5′-end of UBE3A. The PTU is organized (5′-3′) asfollows: SNURF-SNRPN, SNORD107, SNORD64, SNORD109A, SNORD116 (29copies), IPW, SNORD115 (48 copies), SNORD109B, and UBE3A, which isorientated in the opposite direction of the upstream transcripts. Thepolycistronic transcript is alternatively spliced and subject toalternative 3′-processing. SNURF-SNRPN encodes two polypeptides. TheSNORDs are in the introns of a host-gene transcript (SNHG14) and aregenerated by exonucleolytic debranching of the spliced introns. UBE3A-ASrepresents the 3′-end of the transcript that overlaps the UBE3A gene.Most C/D box snoRNAs play a role in ribosome biogenesis where theydirect 2′-O-methylation of ribosomal RNAs (rRNA); however, the snoRNAslocated in the PWS/AS region lack any sequence complementarity to knownrRNAs; however, the SNORD115 snoRNA has been found to change thealternative splicing of the serotonin receptor 2C pre-mRNA.

Disclosed herein is evidence that the 5′-end of UBE3A-AS transcript isimportant for its stability. As disclosed herein, ASOs targeting the5′-end of UBE3A-AS are capable of reducing UBE3A-AS levels, presumablyby stopping transcription of UBE3A-AS, and turning-on the paternal UBE3Aallele.

The term “oligonucleotide” as used herein is defined as it is generallyunderstood by the skilled person as a molecule comprising two or morecovalently linked nucleosides. Such covalently bound nucleosides mayalso be referred to as nucleic acid molecules or oligomers.Oligonucleotides are commonly made in the laboratory by solid-phasechemical synthesis followed by purification. When referring to asequence of the oligonucleotide, reference is made to the sequence ororder of nucleobase moieties, or modifications thereof, of thecovalently linked nucleotides or nucleosides. The oligonucleotidedisclosed herein is man-made, e.g., chemically synthesized. Theoligonucleotide disclosed herein may also comprise one or more modifiednucleosides or nucleotides.

The term “antisense oligonucleotide” as used herein is defined asoligonucleotides capable of modulating expression of a target gene byhybridizing to a target nucleic acid, in particular to a contiguoussequence on a target nucleic acid.

In some embodiments, the antisense oligonucleotides disclosed herein aresingle stranded.

The term “contiguous nucleotide sequence” refers to the region of theoligonucleotide which is complementary to the target nucleic acid. Theterm is used interchangeably herein with the term “contiguous nucleobasesequence” and the term “oligonucleotide motif sequence”. In someembodiments all the nucleotides of the oligonucleotide are present inthe contiguous nucleotide sequence. In some embodiments theoligonucleotide comprises the contiguous nucleotide sequence and may,optionally comprise further nucleotide(s), for example a nucleotidelinker region which may be used to attach a functional group to thecontiguous nucleotide sequence. The nucleotide linker region may or maynot be complementary to the target nucleic acid.

Nucleotides are the building blocks of oligonucleotides andpolynucleotides, and can include both naturally occurring andnon-naturally occurring nucleotides. In nature, nucleotides, such as DNAand RNA nucleotides comprise a ribose sugar moiety, a nucleobase moietyand one or more phosphate groups (which is absent in nucleosides).Nucleosides and nucleotides may also interchangeably be referred to as“units” or “monomers”.

The term “modified nucleoside” or “nucleoside modification” as usedherein refers to nucleosides modified as compared to the equivalent DNAor RNA nucleoside by the introduction of one or more modifications ofthe sugar moiety or the (nucleo)base moiety. In some embodiments, themodified nucleoside comprises a modified sugar moiety. The term modifiednucleoside may also be used herein interchangeably with the term“nucleoside analogue” or modified “units” or modified “monomers”.

The term “modified internucleoside linkage” is defined as generallyunderstood by the skilled person as linkages other than phosphodiester(PO) linkages or natural phosphate linkages that covalently couples twonucleosides together. Nucleotides with modified internucleoside linkageare also termed “modified nucleotides”. In some embodiments, themodified internucleoside linkage increases the nuclease resistance ofthe oligonucleotide compared to a phosphodiester linkage. For naturallyoccurring oligonucleotides, the internucleoside linkage includesphosphate groups creating a phosphodiester bond between adjacentnucleosides. Modified internucleoside linkages are particularly usefulin stabilizing oligonucleotides for in vivo use, and may serve toprotect against nuclease cleavage at regions of DNA or RNA nucleosidesin the oligonucleotide disclosed herein, for example, within the gapregion of a gapmer oligonucleotide, as well as in regions of modifiednucleosides.

In some embodiments, the oligonucleotide comprises one or moreinternucleoside linkages modified from the natural phosphodiester to alinkage that is, for example, more resistant to nuclease attack.Nuclease resistance may be determined by incubating the oligonucleotidein blood serum or by using a nuclease resistance assay [e.g., snakevenom phosphodiesterase (SVPD)], both are well known in the art.Internucleoside linkages which are capable of enhancing the nucleaseresistance of an oligonucleotide are referred to as nuclease resistantinternucleoside linkages.

In some embodiments at least 50% of the internucleoside linkages in theoligonucleotide, or contiguous nucleotide sequence thereof, aremodified, such as at least 60%, such as at least 70%, such as at least80% or such as at least 90% of the internucleoside linkages in theoligonucleotide, or contiguous nucleotide sequence thereof, aremodified. In some embodiments all of the internucleoside linkages of theoligonucleotide, or contiguous nucleotide sequence thereof, aremodified.

It will be recognized that, in some embodiments, the internucleosidelinkages which link the oligonucleotide to a non-nucleotide functionalgroup, such as a conjugate, may be phosphodiester. In some embodiments,the internucleoside linkages which link the oligonucleotide to anon-nucleotide functional group are modified.

In some embodiments all of the internucleoside linkages of theoligonucleotide, or contiguous nucleotide sequence thereof, are nucleaseresistant internucleoside linkages.

Modified internucleoside linkages may, for example, be selected from thegroup comprising phosphorothioate, diphosphorothioate, andboranophosphate. In some embodiments, the modified internucleosidelinkages are compatible with the RNase H recruitment of theoligonucleotide disclosed herein, for example, phosphorothioate,diphosphorothioate, or boranophosphate.

In some embodiments the internucleoside linkage comprises sulphur (S),such as a phosphorothioate internucleoside linkage.

A phosphorothioate internucleoside linkage is particularly useful due tonuclease resistance, beneficial pharmacokinetics and ease ofmanufacture. In preferred embodiments at least 50% of theinternucleoside linkages in the oligonucleotide, or contiguousnucleotide sequence thereof, are phosphorothioate, such as at least 60%,such as at least 70%, such as at least 80%, or such as at least 90% ofthe internucleoside linkages in the oligonucleotide, or contiguousnucleotide sequence thereof, are phosphorothioate. In some embodimentsall of the internucleoside linkages of the oligonucleotide, orcontiguous nucleotide sequence thereof, are phosphorothioate.

In some embodiments, the oligonucleotide comprises one or more neutralinternucleoside linkage, particularly a internucleoside linkage selectedfrom phosphotriester, methylphosphonate, MMI, amide-3, formacetal orthioformacetal. Further internucleoside linkages are disclosed inWO2009/124238 (incorporated herein by reference). In an embodiment theinternucleoside linkage is selected from linkers disclosed inWO2007/031091 (incorporated herein by reference).

Nuclease resistant linkages, such as phosphorothioate linkages, areparticularly useful in oligonucleotide regions capable of recruitingnuclease when forming a duplex with the target nucleic acid, such asregion G for gapmers, or the non-modified nucleoside region of headmersand tailmers. Phosphorothioate linkages may, however, also be useful innon-nuclease recruiting regions and/or affinity enhancing regions suchas regions F and F′ for gapmers, or the modified nucleoside region ofheadmers and tailmers.

Each of the design regions may however comprise internucleoside linkagesother than phosphorothioate, such as phosphodiester linkages, inparticularly in regions where modified nucleosides, such as LNA, protectthe linkage against nuclease degradation. Inclusion of phosphodiesterlinkages, such as one or two linkages, particularly between or adjacentto modified nucleoside units (typically in the non-nuclease recruitingregions) can modify the bioavailability and/or bio-distribution of anoligonucleotide. WO2008/113832 is incorporated herein by reference forthe teaching of oligonucleotides having phosphodiester linkages.

In some embodiments, all the internucleoside linkages in theoligonucleotide are phosphorothioate and/or boranophosphate linkages. Insome embodiments, all the internucleoside linkages in theoligonucleotide are phosphorothioate linkages.

The term nucleobase includes the purine (e.g., adenine and guanine) andpyrimidine (e.g., uracil, thymine, and cytosine) moiety present innucleosides and nucleotides which form hydrogen bonds in nucleic acidhybridization. The term nucleobase also encompasses modified nucleobaseswhich may differ from naturally occurring nucleobases but are functionalduring nucleic acid hybridization. In this context “nucleobase” refersto both naturally occurring nucleobases, such as adenine, guanine,cytosine, thymidine, uracil, xanthine, and hypoxanthine, as well asnon-naturally occurring variants.

In some embodiments the nucleobase moiety is modified by changing thepurine or pyrimidine into a modified purine or pyrimidine, such assubstituted purine or substituted pyrimidine, such as a nucleobasedselected from isocytosine, pseudoisocytosine, 5-methyl-cytosine,5-thiozolo-cytosine, 5-propynyl-cytosine, 5-propynyl-uracil,5-bromouracil 5-thiazolo-uracil, 2-thio-uracil, 2′thio-thymine, inosine,diaminopurine, 6-aminopurine, 2-aminopurine, 2,6-diaminopurine, and2-chloro-6-aminopurine.

The nucleobase moieties may be indicated by the letter code for eachcorresponding nucleobase, e.g., A, T, G, C, or U, wherein each lettermay optionally include modified nucleobases of equivalent function. Forexample, in the exemplified oligonucleotides, the nucleobase moietiesare selected from A, T, G, C, and 5-methyl cytosine (5 mC). Combinationsof these modifications may also be used. For example, 5 mC LNAnucleosides may be used. Likewise, 2′-hydroxmethyl (2′-OMe) 5 mC may beused.

The term “complementarity” describes the capacity for Watson-Crickbase-pairing of nucleosides/nucleotides. Watson-Crick base pairs areguanine (G)-cytosine (C) and adenine (A)-thymine (T)/uracil (U). It willbe understood that oligonucleotides may comprise nucleosides withmodified nucleobases, for example, 5-methyl cytosine is often used inplace of cytosine, and as such the term complementarity encompassesWatson Crick base-paring between non-modified and modified nucleobases.

The term “% complementary” as used herein, refers to the number ofnucleotides in percent of a contiguous nucleotide sequence in a nucleicacid molecule (e.g., oligonucleotide) which, at a given position, arecomplementary to (i.e., form Watson Crick base pairs with) a contiguousnucleotide sequence, at a given position of a separate nucleic acidmolecule (e.g., the target nucleic acid). The percentage is calculatedby counting the number of aligned bases that form pairs between the twosequences, dividing by the total number of nucleotides in theoligonucleotide and multiplying by 100. In such a comparison anucleobase/nucleotide which does not align (form a base pair) is termeda mismatch.

The term “hybridizing” or “hybridizes” as used herein is to beunderstood as two nucleic acid strands (e.g., an oligonucleotide and atarget nucleic acid) forming hydrogen bonds between base pairs onopposite strands thereby forming a duplex. The affinity of the bindingbetween two nucleic acid strands is the strength of the hybridization.It is often described in terms of the melting temperature (Tm) definedas the temperature at which half of the oligonucleotides are duplexedwith the target nucleic acid. At physiological conditions, Tm is notstrictly proportional to the affinity (Mergny and Lacroix, 2003,Oligonucleotides 13:515-537). The standard state Gibbs free energy ΔG°is a more accurate representation of binding affinity and is related tothe dissociation constant (Kd) of the reaction by ΔG°=-RTIn(Kd), where Ris the gas constant and T is the absolute temperature. Therefore, a verylow ΔG° of the reaction between an oligonucleotide and the targetnucleic acid reflects a strong hybridization between the oligonucleotideand target nucleic acid. ΔG° is the energy associated with a reactionwhere aqueous concentrations are 1M, the pH is 7, and the temperature is37° C. The hybridization of oligonucleotides to a target nucleic acid isa spontaneous reaction and for spontaneous reactions ΔG° is less thanzero. ΔG° can be measured experimentally, for example, by use of theisothermal titration calorimetry (ITC) method as described in Hansen etal., 1965, Chem. Comm. 36-38 and Holdgate et al., 2005, Drug DiscovToday. The skilled person will know that commercial equipment isavailable for ΔG° measurements. ΔG° can also be estimated numerically byusing the nearest neighbor model as described by SantaLucia, 1998, ProcNatl Acad Sci USA. 95: 1460-1465 using appropriately derivedthermodynamic parameters described by Sugimoto et al., 1995,Biochemistry 34:11211-11216 and McTigue et al., 2004, Biochemistry43:5388-5405. In order to have the possibility of modulating itsintended nucleic acid target by hybridization, oligonucleotidesdisclosed herein hybridize to a target nucleic acid with estimated ΔG°values below −10 kcal for oligonucleotides that are 10-30 nucleotides inlength. In some embodiments the degree or strength of hybridization ismeasured by the standard state Gibbs free energy ΔG°. Theoligonucleotides may hybridize to a target nucleic acid with estimatedΔG° values below the range of −10 kcal, such as below −15 kcal, such asbelow −20 kcal and such as below −25 kcal for oligonucleotides that are8-30 nucleotides in length. In some embodiments the oligonucleotideshybridize to a target nucleic acid with an estimated ΔG° value of −10 to−60 kcal, such as −12 to −40, such as from −15 to −30 kcal or −16 to −27kcal such as −18 to −25 kcal.

In some embodiments, the disclosed oligonucleotide comprises acontiguous nucleotide sequence of at least 8 nucleotides which iscomplementary to or hybridizes to a target sequence present in thetarget nucleic acid molecule. The contiguous nucleotide sequence (andtherefore the target sequence) comprises of at least 8 contiguousnucleotides, such as 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21,22, 23, 24, 25, 26, 27, 28, 29 or 30 contiguous nucleotides, such asfrom 12-25, such as from 14-18 contiguous nucleotides.

In some embodiments, the disclosed oligonucleotide is a functionalnucleic acid, such as a siRNA, shRNA, or nuclease gRNA, that inhibits,mutates, or deletes the target nucleic acid sequence.

The term “modulation of expression” as used herein is to be understoodas an overall term for an oligonucleotide's ability to alter the amountof UBE3A RNA/protein when compared to the amount of UBE3A beforeadministration of the oligonucleotide. Alternatively modulation ofexpression may be determined by reference to a control experiment wherethe disclosed oligonucleotide is not administered. The modulationeffected by the oligonucleotide is related to its ability to reduce,remove, prevent, lessen, lower or terminate the suppression of thepaternal UBE3A-AS transcript, i.e., by targeting the 5′-end of UBE3A-AS,which is downstream of SNORD115-45 snoRNA. The modulation can also beviewed as the oligonucleotide's ability to restore, increase or enhanceexpression of paternal UBE3A, e.g., by removal or blockage of inhibitorymechanisms affected by UBE3A-AS.

The disclosed oligonucleotide may comprise one or more nucleosides whichhave a modified sugar moiety, i.e., a modification of the sugar moietywhen compared to the ribose sugar moiety found in DNA and RNA. Numerousnucleosides with modification of the ribose sugar moiety have been made,primarily with the aim of improving certain properties ofoligonucleotides, such as affinity and/or nuclease resistance. Suchmodifications include those where the ribose ring structure is modified,e.g., by replacement with a hexose ring (HNA), or a bicyclic ring, whichtypically have a biradicle bridge between the C2 and C4 carbons on theribose ring (LNA), or an unlinked ribose ring which typically lacks abond between the C2 and C3 carbons (e.g., UNA). Other sugar modifiednucleosides include, for example, bicyclohexose nucleosides(WO2011/017521) or tricyclic nucleosides (WO2013/154798). Modifiednucleosides also include nucleosides where the sugar moiety is replacedwith a non-sugar moiety, for example, in the case of peptide nucleicacids (PNA) or morpholino nucleic acids.

Sugar modifications also include modifications made via altering thesubstituent groups on the ribose ring to groups other than hydrogen, orthe 2′-OH group naturally found in DNA and RNA nucleosides. Substituentsmay, for example, be introduced at the 2′, 3′, 4′ or 5′ positions.Nucleosides with modified sugar moieties also include 2′ modifiednucleosides, such as 2′ substituted nucleosides. Indeed, much focus hasbeen spent on developing 2′ substituted nucleosides, and numerous 2′substituted nucleosides have been found to have beneficial propertieswhen incorporated into oligonucleotides, such as enhanced nucleosideresistance and enhanced affinity.

A 2′ sugar modified nucleoside is a nucleoside which has a substituentother than H or —OH at the 2′ position (2′ substituted nucleoside) orcomprises a 2′ linked biradical, and includes 2′ substituted nucleosidesand LNA (2′-4′ biradical bridged) nucleosides. For example, the 2′modified sugar may provide enhanced binding affinity and/or increasednuclease resistance to the oligonucleotide. Examples of 2′ substitutedmodified nucleosides are 2′-O-alkyl-RNA, 2′-O-methyl-RNA (O-Me),2′-alkoxy-RNA, 2′-O-methoxyethyl-RNA (MOE), 2′-amino-DNA, 2′-Fluoro-RNA,and 2′-fluoro-ANA (F-ANA). For further examples, please see Freier &Altmann; Nucl. Acid Res., 1997, 25, 4429-4443 and Uhlmann; Curr. Opinionin Drug Development, 2000, 3(2), 293-213; and Deleavey and Damha,Chemistry and Biology 2012, 19, 937.

Locked Nucleic Acid (LNA) nucleosides are modified nucleosides whichcomprise a linker group (referred to as a biradical or a bridge) betweenC2′ and C4′ of the ribose sugar ring of a nucleotide. These nucleosidesare also termed bridged nucleic acid or bicyclic nucleic acid (BNA) inthe literature.

Nuclease mediated degradation refers to an oligonucleotide capable ofmediating degradation of a complementary nucleotide sequence whenforming a duplex with such a sequence.

In some embodiments, the oligonucleotide may function via nucleasemediated degradation of the target nucleic acid, where the disclosedoligonucleotides are capable of recruiting a nuclease, particularly andendonuclease, preferably endoribonuclease (RNase), such as RNase H.Examples of oligonucleotide designs which operate via nuclease mediatedmechanisms are oligonucleotides which typically comprise a region of atleast 5 or 6 DNA nucleosides and are flanked on one side or both sidesby affinity enhancing nucleosides, for example, gapmers, headmers, andtailmers.

The term “gapmer” as used herein refers to an antisense oligonucleotidewhich comprises a region of RNase H recruiting oligonucleotides (gap)which is flanked 5′ and 3′ by one or more affinity enhancing modifiednucleosides (flanks). Various gapmer designs are described herein.Headmers and tailmers are oligonucleotides capable of recruiting RNase Hwhere one of the flanks is missing, i.e., only one of the ends of theoligonucleotide comprises affinity enhancing modified nucleosides. Forheadmers the 3′ flank is missing (i.e. the 5′ flank comprise affinityenhancing modified nucleosides) and for tailmers the 5′ flank is missing(i.e. the 3′ flank comprises affinity enhancing modified nucleosides).

Conjugation of the disclosed oligonucleotide to one or morenon-nucleotide moieties may improve the pharmacology of theoligonucleotide, e.g., by affecting the activity, cellular distribution,cellular uptake, or stability of the oligonucleotide. In someembodiments the conjugate moiety modify or enhance the pharmacokineticproperties of the oligonucleotide by improving cellular distribution,bioavailability, metabolism, excretion, permeability, and/or cellularuptake of the oligonucleotide. In particular the conjugate may targetthe oligonucleotide to a specific organ, tissue, or cell type andthereby enhance the effectiveness of the oligonucleotide in that organ,tissue, or cell type. At the same time the conjugate may serve to reduceactivity of the oligonucleotide in non-target cell types, tissues ororgans, e.g., off target activity or activity in non-target cell types,tissues or organs. WO 93/07883 and WO 2013/033230 provides suitableconjugate moieties, which are hereby incorporated by reference. WO2012/143379 provides a method of delivering a drug across theblood-brain-barrier by conjugation to an antibody fragment with affinityto the transferrin receptor, which are hereby incorporated by reference.

In some embodiments, the non-nucleotide moiety (conjugate moiety) isselected from the group consisting of carbohydrates, cell surfacereceptor ligands, drug substances, hormones, lipophilic substances,polymers, proteins, peptides, toxins (e.g., bacterial toxins), vitamins,viral proteins (e.g., capsids) or combinations thereof. In someembodiments the non-nucleotide moiety an antibody or antibody fragment,such as an antibody or antibody fragment that facilitates deliveryacross the blood-brain-barrier, in particular an antibody or antibodyfragment targeting the transferrin receptor.

The term “subject” refers to any individual who is the target ofadministration or treatment. The subject can be a vertebrate, forexample, a mammal. Thus, the subject can be a human or veterinarypatient. The term “patient” refers to a subject under the treatment of aclinician, e.g., physician.

The term “therapeutically effective” refers to the amount of thecomposition used is of sufficient quantity to ameliorate one or morecauses or symptoms of a disease or disorder. Such amelioration onlyrequires a reduction or alteration, not necessarily elimination.

The term “pharmaceutically acceptable” refers to those compounds,materials, compositions, and/or dosage forms, which are within the scopeof sound medical judgment, suitable for use in contact with the tissuesof human beings and animals without excessive toxicity, irritation,allergic response, or other problems or complications commensurate witha reasonable benefit/risk ratio.

The term “treatment” refers to the medical management of a patient withthe intent to cure, ameliorate, stabilize, or prevent a disease,pathological condition, or disorder. This term includes activetreatment, that is, treatment directed specifically toward theimprovement of a disease, pathological condition, or disorder, and alsoincludes causal treatment, that is, treatment directed toward removal ofthe cause of the associated disease, pathological condition, ordisorder. In addition, this term includes palliative treatment, that is,treatment designed for the relief of symptoms rather than the curing ofthe disease, pathological condition, or disorder; preventativetreatment, that is, treatment directed to minimizing or partially orcompletely inhibiting the development of the associated disease,pathological condition, or disorder; and supportive treatment, that is,treatment employed to supplement another specific therapy directedtoward the improvement of the associated disease, pathologicalcondition, or disorder.

The term “inhibit” refers to a decrease in an activity, response,condition, disease, or other biological parameter, which those skilledin the art will appreciate may be assessed at a particular point intime, such that in some embodiments, inhibition may be or comprise adelay in onset or reduction in frequency. In some embodiments,inhibition can include, but is not limited to, the complete ablation ofthe activity, response, condition, or disease. This may also include,for example, a 10% reduction in the activity, response, condition, ordisease as compared to the native or control level. Thus, the reductioncan be a 10, 20, 30, 40, 50, 60, 70, 80, 90, 100%, or any amount ofreduction in between as compared to native or control levels.

Antisense oligonucleotides (ASOs) were designed to target exons at the5′- end of the SNORD115 host-gene transcript (AF400500), whichencompasses SNORD115-46, SNORD115-47, SNORD115-48, and SNORD109B snoRNAsand is thought to represent the 5′-end of the UBE3A antisense transcript(UBE3A-AS). In particular the target nucleic acid can be the 5′-end ofUBE3A-AS, corresponding to position 25,511,577 to 25,516,681 on humanchromosome 15 human genome assembly hg19. In some embodiments, thetarget nucleic acid is one of five exons located in the 5′-end ofUBE3A-AS, which can correspond to positions 25,511,577 to 25,511,761(exon 1), 25,512,059 to 25,512,191 (exon 2), 25,513,476 to 25,513,600(exon 3), 25,514,752 to 25,514,880 (exon 4), and 25,516,565 to25,516,681 (exon 5).

Therefore, in some embodiments, the target nucleic acid is

(Exon 1, SEQ ID NO: 1) ATGATGATATGGAAGAAAAGCACTCTTTGGCCTGTTGTGACTGGGACAGTTGACAGCACCCAGGTGTCCTTTAATGAAAATGCTCTTGACACCAATGCATCCTAGCATCACAGCTTCAGGAAGCCTTCTCAAGTGTGCATGGGGAGTACTATGTCTTTCATCAATAATGAAATCTTCTGATTTG.

In some embodiments, the target nucleic acid is

(Exon 2, SEQ ID NO: 2) TAAGACATGCTGCCAAGAGATGTGCCATTCTATTATAAAAGATCAGTAGCTTCCTTTACCGACGTGTATATTCTATCTAGAACATTGAGCTATGGAAGACTCCCACCTAAGGGAATTAGTTTTACACCTTCAG.

In some embodiments, the target nucleic acid is

(Exon 3, SEQ ID NO: 3) ATAAAGACTGCTGAGAAGAGCACCCTCTGGTGTTGTCACAGAGGCAAGTGCTACCGCACAGGCATGCTGCAGTGAATTTAACTGATCCTCTGTCCCTGCAACCGTTGTTTAAGGATGCTATTCTG.

In some embodiments, the target nucleic acid is

(Exon 4, SEQ ID NO: 4) AAAAGACTGTGGAGGAAGAAAACCCTTTACCCTGTTGTTCAGGGAGAAACTGACACCACTCAACTGCCTGGCACTGAAAATGTGGCATCCAGTCCACTTTACCATCAGTGTTTAAGGAAACCATCTCTG.

In some embodiments, the target nucleic acid is

(Exon 5, SEQ ID NO: 5) ATAAGGATGACTGAGGAAGAGTACTCTTTGGCTTGTTGACACCAGCACAGCTGACACACCCAGATATCTGTTTGGTCTCCTGTGAACTTTCAACCAGG ATTTAAGGATGCCACTCTG.

In some embodiments, the disclosed ASO has the nucleic acid sequenceTAGAGGTGAAGGCCAGGCAC (ASO-1, SEQ ID NO:6).

In some embodiments, the ASO has the nucleic acid sequence

(ASO-2, SEQ ID NO: 7) GTACTCTTCCTCAGTCATCC.

In some embodiments, the disclosed ASO has the nucleic acid sequence

(ASO-3, SEQ ID NO: 8) TGTCAGTTTCTCCCTGAACA.

In some embodiments, the disclosed ASO has the nucleic acid sequence

(ASO-4, SEQ ID NO: 9) TAGAATGGCACATCTCTTGG.

In some embodiments, the disclosed ASO has the nucleic acid sequence

(ASO-6, SEQ ID NO: 10) GTTTTCTTCCTCCACAGTCT.

In some embodiments, the disclosed ASO has the nucleic acid sequence

(ASO-7, SEQ ID NO: 11) CTGGTGTCAACAAGCCAAAG.

Additional ASOs that can target exon 1 of the 3′-end of the SNORD115region are provided below in Table 1. Example ASOs that can target exon2 of the 3′-end of the SNORD115 are provided below in Table 2. ExampleASOs that can target exon 3 of the 3′-end of the SNORD115 are providedbelow in Table 3. Example ASOs that can target exon 4 of the 3′-end ofthe SNORD115 are provided below in Table 4. Example ASOs that can targetexon 5 of the 3′-end of the SNORD115 are provided below in Table 5.

TABLE 1 Exon 1 ASOs Target Sequence (5′→3′) ASO (5′→3′)GAAAAUGCUCUUGACACC (SEQ ID NO: 12) GGTGTCAAGAGCATTTTC (SEQ ID NO: 15)GAAAAUGCUCUUGACACCA (SEQ ID NO: 13) TGGTGTCAAGAGCATTTTC (SEQ ID NO: 16)GAAAAUGCUCUUGACACCAA (SEQ ID NO: 14)TTGGTGTCAAGAGCATTTTC (SEQ ID NO: 17)

TABLE 2 Exon 2 ASOs Target Sequence (5′→3′) ASO (5′→3′)CAUGCUGCCAAGAGAUGU (SEQ ID NO: 18) ACATCTCTTGGCAGCATG (SEQ ID NO: 67)CAUGCUGCCAAGAGAUGUG (SEQ ID NO: 19) CACATCTCTTGGCAGCATG (SEQ ID NO: 68)CAUGCUGCCAAGAGAUGUGC (SEQ ID NO: 20)GCACATCTCTTGGCAGCATG (SEQ ID NO: 69) AUGCUGCCAAGAGAUGUG (SEQ ID NO: 21)CACATCTCTTGGCAGCAT (SEQ ID NO: 70) AUGCUGCCAAGAGAUGUGC (SEQ ID NO: 22)GCACATCTCTTGGCAGCAT (SEQ ID NO: 71) AUGCUGCCAAGAGAUGUGCC (SEQ ID NO: 23)GGCACATCTCTTGGCAGCAT (SEQ ID NO: 72) UGCUGCCAAGAGAUGUGCC (SEQ ID NO: 24)GGCACATCTCTTGGCAGCA (SEQ ID NO: 73) UGCUGCCAAGAGAUGUGCCA (SEQ ID NO: 25)TGGCACATCTCTTGGCAGCA (SEQ ID NO: 74) GCUGCCAAGAGAUGUGCCA (SEQ ID NO: 26)TGGCACATCTCTTGGCAGC (SEQ ID NO: 75) GCUGCCAAGAGAUGUGCCAU (SEQ ID NO: 27)ATGGCACATCTCTTGGCAGC (SEQ ID NO: 76) CUGCCAAGAGAUGUGCCA(SEQ ID NO: 28)TGGCACATCTCTTGGCAG (SEQ ID NO: 77) CUGCCAAGAGAUGUGCCAU (SEQ ID NO: 29)ATGGCACATCTCTTGGCAG (SEQ ID NO: 78) CUGCCAAGAGAUGUGCCAUU (SEQ ID NO: 30)AATGGCACATCTCTTGGCAG (SEQ ID NO: 79) UGCCAAGAGAUGUGCCAU (SEQ ID NO: 31)ATGGCACATCTCTTGGCA (SEQ ID NO: 80) UGCCAAGAGAUGUGCCAUU (SEQ ID NO: 32)AATGGCACATCTCTTGGCA (SEQ ID NO: 81) UGCCAAGAGAUGUGCCAUUC (SEQ ID NO: 33)GAATGGCACATCTCTTGGCA (SEQ ID NO: 82) GCCAAGAGAUGUGCCAUU (SEQ ID NO: 34)AATGGCACATCTCTTGGC (SEQ ID NO: 83) GCCAAGAGAUGUGCCAUUC (SEQ ID NO: 35)GAATGGCACATCTCTTGGC (SEQ ID NO: 84) GCCAAGAGAUGUGCCAUUCU (SEQ ID NO: 36)AGAATGGCACATCTCTTGGC (SEQ ID NO: 85) CCAAGAGAUGUGCCAUUC (SEQ ID NO: 37)GAATGGCACATCTCTTGG (SEQ ID NO: 86) CCAAGAGAUGUGCCAUUCU (SEQ ID NO: 38)AGAATGGCACATCTCTTGG (SEQ ID NO: 87) CCAAGAGAUGUGCCAUUCUA (SEQ ID NO: 39)TAGAATGGCACATCTCTTGG (SEQ ID NO: 88) CAAGAGAUGUGCCAUUCU (SEQ ID NO: 40)AGAATGGCACATCTCTTG (SEQ ID NO: 89) CAAGAGAUGUGCCAUUCUA (SEQ ID NO: 41)TAGAATGGCACATCTCTTG (SEQ ID NO: 90) CAAGAGAUGUGCCAUUCUAU (SEQ ID NO: 42)ATAGAATGGCACATCTCTTG (SEQ ID NO: 91) UCCUUUACCGACGUGUAU (SEQ ID NO: 43)ATACACGTCGGTAAAGGA (SEQ ID NO: 92) UCCUUUACCGACGUGUAUA (SEQ ID NO: 44)TATACACGTCGGTAAAGGA (SEQ ID NO: 93) UCCUUUACCGACGUGUAUAU (SEQ ID NO: 45)ATATACACGTCGGTAAAGGA (SEQ ID NO: 94) CCUUUACCGACGUGUAUA (SEQ ID NO: 46)TATACACGTCGGTAAAGG (SEQ ID NO: 95) CCUUUACCGACGUGUAUAU (SEQ ID NO: 47)ATATACACGTCGGTAAAGG (SEQ ID NO: 96) CCUUUACCGACGUGUAUAUU (SEQ ID NO: 48)AATATACACGTCGGTAAAGG (SEQ ID NO: 97)ACCGACGUGUAUAUUCUAUC (SEQ ID NO: 49)GATAGAATATACACGTCGGT (SEQ ID NO: 98) CCGACGUGUAUAUUCUAUC (SEQ ID NO: 50)GATAGAATATACACGTCGG (SEQ ID NO: 99) CCGACGUGUAUAUUCUAUCU (SEQ ID NO: 51)AGATAGAATATACACGTCGG (SEQ ID NO: 100)UCUAGAACAUUGAGCUAUGG (SEQ ID NO: 52)CCATAGCTCAATGTTCTAGA (SEQ ID NO: 101) CAUUGAGCUAUGGAAGAC (SEQ ID NO: 53)GTCTTCCATAGCTCAATG (SEQ ID NO: 102) CUAUGGAAGACUCCCACCUA (SEQ ID NO: 54)TAGGTGGGAGTCTTCCATAG (SEQ ID NO: 103)UAUGGAAGACUCCCACCUA (SEQ ID NO: 55) TAGGTGGGAGTCTTCCATA (SEQ ID NO: 104)UAUGGAAGACUCCCACCUAA (SEQ ID NO: 56)TTAGGTGGGAGTCTTCCATA (SEQ ID NO: 105) AUGGAAGACUCCCACCUA (SEQ ID NO: 57)TAGGTGGGAGTCTTCCAT (SEQ ID NO: 106) AUGGAAGACUCCCACCUAA (SEQ ID NO: 58)TTAGGTGGGAGTCTTCCAT (SEQ ID NO: 107) UGGAAGACUCCCACCUAA (SEQ ID NO: 59)TTAGGTGGGAGTCTTCCA (SEQ ID NO: 108) GACUCCCACCUAAGGGAAUU (SEQ ID NO: 60)AATTCCCTTAGGTGGGAGTC (SEQ ID NO: 109) ACUCCCACCUAAGGGAAU (SEQ ID NO: 61)ATTCCCTTAGGTGGGAGT (SEQ ID NO: 110) ACUCCCACCUAAGGGAAUU (SEQ ID NO: 62)AATTCCCTTAGGTGGGAGT (SEQ ID NO: 111)ACUCCCACCUAAGGGAAUUA (SEQ ID NO: 63)TAATTCCCTTAGGTGGGAGT (SEQ ID NO: 112) CUCCCACCUAAGGGAAUU (SEQ ID NO: 64)AATTCCCTTAGGTGGGAG (SEQ ID NO: 113) CUCCCACCUAAGGGAAUUA (SEQ ID NO: 65)TAATTCCCTTAGGTGGGAG (SEQ ID NO: 114) UCCCACCUAAGGGAAUUA (SEQ ID NO: 66)TAATTCCCTTAGGTGGGA (SEQ ID NO: 115)

TABLE 3 Exon 3 ASOs Target Sequence (5′→3′) ASO (5′→3′)GAUAAAGACUGCUGAGAAGA (SEQ ID NO: 116)TCTTCTCAGCAGTCTTTATC (SEQ ID NO: 139)AUAAAGACUGCUGAGAAGAG (SEQ ID NO: 117)CTCTTCTCAGCAGTCTTTAT (SEQ ID NO: 140)UAAAGACUGCUGAGAAGAGC (SEQ ID NO: 118)GCTCTTCTCAGCAGTCTTTA (SEQ ID NO: 141)AAAGACUGCUGAGAAGAGCA (SEQ ID NO: 119)TGCTCTTCTCAGCAGTCTTT (SEQ ID NO: 142)AAGACUGCUGAGAAGAGCAC (SEQ ID NO: 120)GTGCTCTTCTCAGCAGTCTT (SEQ ID NO: 143)AGACUGCUGAGAAGAGCACC (SEQ ID NO: 121)GGTGCTCTTCTCAGCAGTCT (SEQ ID NO: 144)GACUGCUGAGAAGAGCACCC (SEQ ID NO: 122)GGGTGCTCTTCTCAGCAGTC (SEQ ID NO: 145)CAAGUGCUACCGCACAGGCA (SEQ ID NO: 123)TGCCTGTGCGGTAGCACTTG (SEQ ID NO: 146)AAGUGCUACCGCACAGGCAU (SEQ ID NO: 124)ATGCCTGTGCGGTAGCACTT (SEQ ID NO: 147)AGUGCUACCGCACAGGCAUG (SEQ ID NO: 125)CATGCCTGTGCGGTAGCACT (SEQ ID NO: 148)UGCUACCGCACAGGCAUGCU (SEQ ID NO: 126)AGCATGCCTGTGCGGTAGCA (SEQ ID NO: 149)UACCGCACAGGCAUGCUGCA (SEQ ID NO: 127)TGCAGCATGCCTGTGCGGTA (SEQ ID NO: 150)GCACAGGCAUGCUGCAGUGA (SEQ ID NO: 128)TCACTGCAGCATGCCTGTGC (SEQ ID NO: 151)CACAGGCAUGCUGCAGUGAA (SEQ ID NO: 129)TTCACTGCAGCATGCCTGTG (SEQ ID NO: 152)ACAGGCAUGCUGCAGUGAAU (SEQ ID NO: 130)ATTCACTGCAGCATGCCTGT (SEQ ID NO: 153)CAGGCAUGCUGCAGUGAAUU (SEQ ID NO: 131)AATTCACTGCAGCATGCCTG (SEQ ID NO: 154)AGGCAUGCUGCAGUGAAUUU (SEQ ID NO: 132)AAATTCACTGCAGCATGCCT (SEQ ID NO: 155)GGCAUGCUGCAGUGAAUUUA (SEQ ID NO: 133)TAAATTCACTGCAGCATGCC (SEQ ID NO: 156)GCAUGCUGCAGUGAAUUUAA (SEQ ID NO: 134)TTAAATTCACTGCAGCATGC (SEQ ID NO: 157)CAUGCUGCAGUGAAUUUAAC (SEQ ID NO: 135)GTTAAATTCACTGCAGCATG (SEQ ID NO: 158)GCAGUGAAUUUAACUGAUCC (SEQ ID NO: 136)GGATCAGTTAAATTCACTGC (SEQ ID NO: 159)UCCCUGCAACCGUUGUUUAA (SEQ ID NO: 137)TTAAACAACGGTTGCAGGGA (SEQ ID NO: 160)CCCUGCAACCGUUGUUUAAG (SEQ ID NO: 138)CTTAAACAACGGTTGCAGGG (SEQ ID NO: 161)

TABLE 4 Exon 4 ASOs Target Sequence (5′→3′) ASO (5′→3′)AAAAGACUGUGGAGGAAGA (SEQ ID NO: 162)TCTTCCTCCACAGTCTTTT (SEQ ID NO: 237)AAAAGACUGUGGAGGAAGAA (SEQ ID NO: 163)TTCTTCCTCCACAGTCTTTT (SEQ ID NO: 238)AAAGACUGUGGAGGAAGAA (SEQ ID NO: 164)TTCTTCCTCCACAGTCTTT (SEQ ID NO: 239)AAAGACUGUGGAGGAAGAAA (SEQ ID NO: 165)TTTCTTCCTCCACAGTCTTT (SEQ ID NO: 240)AAGACUGUGGAGGAAGAAAA(SEQ ID NO: 166)TTTTCTTCCTCCACAGTCTT (SEQ ID NO: 241)AGACUGUGGAGGAAGAAAAC (SEQ ID NO: 167)GTTTTCTTCCTCCACAGTCT (SEQ ID NO: 242)ACUGUGGAGGAAGAAAAC (SEQ ID NO: 168) GTTTTCTTCCTCCACAGT (SEQ ID NO: 243)ACUGUGGAGGAAGAAAACC (SEQ ID NO: 169)GGTTTTCTTCCTCCACAGT (SEQ ID NO: 244)ACUGUGGAGGAAGAAAACCC (SEQ ID NO: 170)GGGTTTTCTTCCTCCACAGT (SEQ ID NO: 245)CUGUGGAGGAAGAAAACC (SEQ ID NO: 171) GGTTTTCTTCCTCCACAG (SEQ ID NO: 246)CUGUGGAGGAAGAAAACCC (SEQ ID NO: 172)GGGTTTTCTTCCTCCACAG (SEQ ID NO: 247)AAAACCCUUUACCCUGUUG (SEQ ID NO: 173)CAACAGGGTAAAGGGTTTT (SEQ ID NO: 248)AAAACCCUUUACCCUGUUGU (SEQ ID NO: 174)ACAACAGGGTAAAGGGTTTT (SEQ ID NO: 249)AAACCCUUUACCCUGUUGUU (SEQ ID NO: 175)AACAACAGGGTAAAGGGTTT (SEQ ID NO: 250)UUGUUCAGGGAGAAACUG (SEQ ID NO: 176) CAGTTTCTCCCTGAACAA (SEQ ID NO: 251)UUGUUCAGGGAGAAACUGAC (SEQ ID NO: 177)GTCAGTTTCTCCCTGAACAA (SEQ ID NO: 252)UGUUCAGGGAGAAACUGA (SEQ ID NO: 178) TCAGTTTCTCCCTGAACA (SEQ ID NO: 253)UGUUCAGGGAGAAACUGAC (SEQ ID NO: 179)GTCAGTTTCTCCCTGAACA (SEQ ID NO: 254)UGUUCAGGGAGAAACUGACA(SEQ ID NO: 180)TGTCAGTTTCTCCCTGAACA (SEQ ID NO: 255)GUUCAGGGAGAAACUGACA (SEQ ID NO: 181)TGTCAGTTTCTCCCTGAAC (SEQ ID NO: 256)UCAGGGAGAAACUGACACCA (SEQ ID NO: 182)TGGTGTCAGTTTCTCCCTGA (SEQ ID NO: 257)CAGGGAGAAACUGACACCA (SEQ ID NO: 183)TGGTGTCAGTTTCTCCCTG (SEQ ID NO: 258) AGGGAGAAACUGACACCA (SEQ ID NO: 184)TGGTGTCAGTTTCTCCCT (SEQ ID NO: 259) AGGGAGAAACUGACACCAC (SEQ ID NO: 185)GTGGTGTCAGTTTCTCCCT (SEQ ID NO: 260)AGGGAGAAACUGACACCACU (SEQ ID NO: 186)AGTGGTGTCAGTTTCTCCCT (SEQ ID NO: 261)GGGAGAAACUGACACCAC (SEQ ID NO: 187) GTGGTGTCAGTTTCTCCC (SEQ ID NO: 262)GGGAGAAACUGACACCACU (SEQ ID NO: 188)AGTGGTGTCAGTTTCTCCC (SEQ ID NO: 263)GGGAGAAACUGACACCACUC (SEQ ID NO: 189)GAGTGGTGTCAGTTTCTCCC (SEQ ID NO: 264)GGAGAAACUGACACCACU (SEQ ID NO: 190) AGTGGTGTCAGTTTCTCC (SEQ ID NO: 265)GGAGAAACUGACACCACUC (SEQ ID NO: 191)GAGTGGTGTCAGTTTCTCC (SEQ ID NO: 266)GGAGAAACUGACACCACUCA (SEQ ID NO: 192)TGAGTGGTGTCAGTTTCTCC (SEQ ID NO: 267)GAGAAACUGACACCACUC (SEQ ID NO: 193) GAGTGGTGTCAGTTTCTC (SEQ ID NO: 268)GAGAAACUGACACCACUCA (SEQ ID NO: 194)TGAGTGGTGTCAGTTTCTC (SEQ ID NO: 269)GAGAAACUGACACCACUCAA (SEQ ID NO: 195)TTGAGTGGTGTCAGTTTCTC (SEQ ID NO: 270)AGAAACUGACACCACUCA (SEQ ID NO: 196) TGAGTGGTGTCAGTTTCT (SEQ ID NO: 271)AGAAACUGACACCACUCAA (SEQ ID NO: 197)TTGAGTGGTGTCAGTTTCT (SEQ ID NO: 272)AGAAACUGACACCACUCAAC (SEQ ID NO: 198)GTTGAGTGGTGTCAGTTTCT (SEQ ID NO: 273)GAAACUGACACCACUCAA (SEQ ID NO: 199) TTGAGTGGTGTCAGTTTC (SEQ ID NO: 274)GAAACUGACACCACUCAAC (SEQ ID NO: 200)GTTGAGTGGTGTCAGTTTC (SEQ ID NO: 275)GAAACUGACACCACUCAACU (SEQ ID NO: 201)AGTTGAGTGGTGTCAGTTTC (SEQ ID NO: 276)AAACUGACACCACUCAAC (SEQ ID NO: 202) GTTGAGTGGTGTCAGTTT (SEQ ID NO: 277)AAACUGACACCACUCAACU (SEQ ID NO: 203)AGTTGAGTGGTGTCAGTTT (SEQ ID NO: 278)AAACUGACACCACUCAACUG (SEQ ID NO: 204)CAGTTGAGTGGTGTCAGTTT (SEQ ID NO: 279)AACUGACACCACUCAACU (SEQ ID NO: 205) AGTTGAGTGGTGTCAGTT (SEQ ID NO: 280)AACUGACACCACUCAACUG (SEQ ID NO: 206)CAGTTGAGTGGTGTCAGTT (SEQ ID NO: 281)AACUGACACCACUCAACUGC (SEQ ID NO: 207)GCAGTTGAGTGGTGTCAGTT (SEQ ID NO: 282)ACUGACACCACUCAACUG (SEQ ID NO: 208) CAGTTGAGTGGTGTCAGT (SEQ ID NO: 283)ACUGACACCACUCAACUGC (SEQ ID NO: 209)GCAGTTGAGTGGTGTCAGT (SEQ ID NO: 284)ACUGACACCACUCAACUGCC (SEQ ID NO: 210)GGCAGTTGAGTGGTGTCAGT (SEQ ID NO: 285)CUGACACCACUCAACUGC (SEQ ID NO: 211) GCAGTTGAGTGGTGTCAG (SEQ ID NO: 286)CUGACACCACUCAACUGCC (SEQ ID NO: 212)GGCAGTTGAGTGGTGTCAG (SEQ ID NO: 287)CUGACACCACUCAACUGCCU (SEQ ID NO: 213)AGGCAGTTGAGTGGTGTCAG (SEQ ID NO: 288)UGACACCACUCAACUGCC (SEQ ID NO: 214) GGCAGTTGAGTGGTGTCA (SEQ ID NO: 289)UGACACCACUCAACUGCCU (SEQ ID NO: 215)AGGCAGTTGAGTGGTGTCA (SEQ ID NO: 290)UGACACCACUCAACUGCCUG (SEQ ID NO: 216)CAGGCAGTTGAGTGGTGTCA (SEQ ID NO: 291)GACACCACUCAACUGCCU (SEQ ID NO: 217) AGGCAGTTGAGTGGTGTC (SEQ ID NO: 292)GACACCACUCAACUGCCUG (SEQ ID NO: 218)CAGGCAGTTGAGTGGTGTC (SEQ ID NO: 293)GACACCACUCAACUGCCUGG (SEQ ID NO: 219)CCAGGCAGTTGAGTGGTGTC (SEQ ID NO: 294)ACACCACUCAACUGCCUG (SEQ ID NO: 220) CAGGCAGTTGAGTGGTGT (SEQ ID NO: 295)ACACCACUCAACUGCCUGG (SEQ ID NO: 221)CCAGGCAGTTGAGTGGTGT (SEQ ID NO: 296)ACACCACUCAACUGCCUGGC (SEQ ID NO: 222)GCCAGGCAGTTGAGTGGTGT (SEQ ID NO: 297)CACCACUCAACUGCCUGGCA (SEQ ID NO: 223)TGCCAGGCAGTTGAGTGGTG (SEQ ID NO: 298)GAAAAUGUGGCAUCCAGU (SEQ ID NO: 224) ACTGGATGCCACATTTTC (SEQ ID NO: 299)AAAAUGUGGCAUCCAGUC (SEQ ID NO: 225) GACTGGATGCCACATTTT (SEQ ID NO: 300)GCAUCCAGUCCACUUUACCA (SEQ ID NO: 226)TGGTAAAGTGGACTGGATGC (SEQ ID NO: 301)CAUCCAGUCCACUUUACC (SEQ ID NO: 227) GGTAAAGTGGACTGGATG (SEQ ID NO: 302)CAUCCAGUCCACUUUACCA (SEQ ID NO: 228)TGGTAAAGTGGACTGGATG (SEQ ID NO: 303)CAUCCAGUCCACUUUACCAU (SEQ ID NO: 229)ATGGTAAAGTGGACTGGATG (SEQ ID NO: 304)AUCCAGUCCACUUUACCA (SEQ ID NO: 230) TGGTAAAGTGGACTGGAT (SEQ ID NO: 305)AUCCAGUCCACUUUACCAU (SEQ ID NO: 231)ATGGTAAAGTGGACTGGAT (SEQ ID NO: 306)AUCCAGUCCACUUUACCAUC (SEQ ID NO: 232)GATGGTAAAGTGGACTGGAT (SEQ ID NO: 307)GUUUAAGGAAACCAUCUCUG (SEQ ID NO: 233)CAGAGATGGTTTCCTTAAAC (SEQ ID NO: 308)UUUAAGGAAACCAUCUCUGG (SEQ ID NO: 234)CCAGAGATGGTTTCCTTAAA (SEQ ID NO: 309)UUAAGGAAACCAUCUCUGG (SEQ ID NO: 235)CCAGAGATGGTTTCCTTAA (SEQ ID NO: 310) UAAGGAAACCAUCUCUGG (SEQ ID NO: 236)CCAGAGATGGTTTCCTTA (SEQ ID NO: 311)

TABLE 5 Exon 5 ASOs Target Sequence (5′→3′) ASO (5′→3′)AUAAGGAUGACUGAGGAAG (SEQ ID NO: 312)CTTCCTCAGTCATCCTTAT (SEQ ID NO: 335)AUAAGGAUGACUGAGGAAGA (SEQ ID NO: 313)TCTTCCTCAGTCATCCTTAT (SEQ ID NO: 336)UAAGGAUGACUGAGGAAG (SEQ ID NO: 314) CTTCCTCAGTCATCCTTA (SEQ ID NO: 337)UAAGGAUGACUGAGGAAGA (SEQ ID NO: 315)TCTTCCTCAGTCATCCTTA (SEQ ID NO: 338)UAAGGAUGACUGAGGAAGAG (SEQ ID NO: 316)CTCTTCCTCAGTCATCCTTA (SEQ ID NO: 339)AAGGAUGACUGAGGAAGA (SEQ ID NO: 317) TCTTCCTCAGTCATCCTT (SEQ ID NO: 340)AAGGAUGACUGAGGAAGAG (SEQ ID NO: 318)CTCTTCCTCAGTCATCCTT (SEQ ID NO: 341)AAGGAUGACUGAGGAAGAGU (SEQ ID NO: 319)ACTCTTCCTCAGTCATCCTT (SEQ ID NO: 342)AGGAUGACUGAGGAAGAG (SEQ ID NO: 320) CTCTTCCTCAGTCATCCT (SEQ ID NO: 343)AGGAUGACUGAGGAAGAGU (SEQ ID NO: 321)ACTCTTCCTCAGTCATCCT (SEQ ID NO: 344)AGGAUGACUGAGGAAGAGUA (SEQ ID NO: 322)TACTCTTCCTCAGTCATCCT (SEQ ID NO: 345)GGAUGACUGAGGAAGAGU (SEQ ID NO: 323) ACTCTTCCTCAGTCATCC (SEQ ID NO: 346)GGAUGACUGAGGAAGAGUA (SEQ ID NO: 324)TACTCTTCCTCAGTCATCC (SEQ ID NO: 347)GGAUGACUGAGGAAGAGUAC (SEQ ID NO: 325)GTACTCTTCCTCAGTCATCC (SEQ ID NO: 348)GAUGACUGAGGAAGAGUA (SEQ ID NO: 326) TACTCTTCCTCAGTCATC (SEQ ID NO: 349)GAUGACUGAGGAAGAGUAC (SEQ ID NO: 327)GTACTCTTCCTCAGTCATC (SEQ ID NO: 350)GAUGACUGAGGAAGAGUACU (SEQ ID NO: 328)AGTACTCTTCCTCAGTCATC (SEQ ID NO: 351)AUGACUGAGGAAGAGUAC (SEQ ID NO: 329) GTACTCTTCCTCAGTCAT (SEQ ID NO: 352)AUGACUGAGGAAGAGUACU (SEQ ID NO: 330)AGTACTCTTCCTCAGTCAT (SEQ ID NO: 353)AUGACUGAGGAAGAGUACUC (SEQ ID NO: 331)GAGTACTCTTCCTCAGTCAT (SEQ ID NO: 354)UGACUGAGGAAGAGUACU (SEQ ID NO: 332) AGTACTCTTCCTCAGTCA (SEQ ID NO: 355)UGACUGAGGAAGAGUACUC (SEQ ID NO: 333)GAGTACTCTTCCTCAGTCA (SEQ ID NO: 356)UGACUGAGGAAGAGUACUCU (SEQ ID NO: 334)AGAGTACTCTTCCTCAGTCA (SEQ ID NO: 357)

The disclosed oligonucleotide is capable of modulating expression ofpaternal UBE3A, in particular induction or up-regulation of paternallyexpressed UBE3A in neuronal cells. The modulation is achieved byhybridizing to the 5′-end of UBE3A-AS. In certain embodiments theoligonucleotide disclosed herein hybridizes to a sub-sequence of thetarget nucleic acid of SEQ ID NO:1 with a ΔG° below −10 kcal, such aswith a ΔG° between −10 to −60 kcal, such as −12 to −40, such as from −15to −30 kcal or −16 to −27 kcal such as −18 to −25 kcal.

In some embodiments the disclosed oligonucleotides are capable ofincreasing the expression of UBE3A by least 20% compared to theexpression level of UBE3A in a neuronal cell treated with saline or anon-targeting oligonucleotide, more preferably by at least 30%, 35%,40%, 45%, 50%, 55%, 60%, 80%, 100%, 120%, 150%, 160%, 170%, 180%, 190%,200%, 210%, 220%, 230%, 240% or 250% compared to the expression level ofUBE3A in a neuronal cell treated with saline or a non-targetingoligonucleotide. In some embodiments, the disclosed oligonucleotides arecapable of decreasing the level of the SNHG14 transcript downstream of

SNORD115-45 by at least 20% compared to the level of the SNHG14transcript downstream of SNORD1115-45 in a neuronal cell treated withsaline or a non-targeting oligonucleotide, more preferably by at least30%, 40%, 50%, 60%, 70%, 80%, 90% or 95% compared to the level of theSNHG14 transcript downstream of SNORD115-45 in a neuronal cell treatedwith saline or a non-targeting oligonucleotide.

Target modulation by the disclosed oligonucleotide is triggered byhybridization between a contiguous nucleotide sequence of theoligonucleotide and the target nucleic acid. In some embodiments thedisclosed oligonucleotide comprises mismatches between theoligonucleotide and the target nucleic acid. Despite mismatcheshybridization to the target nucleic acid may still be sufficient to showa desired modulation of UBE3A expression. Reduced binding affinityresulting from mismatches may advantageously be compensated by increasednumber of nucleotides in the oligonucleotide and/or an increased numberof modified nucleosides capable of increasing the binding affinity tothe target, such as 2′ modified nucleosides, including LNA, presentwithin the oligonucleotide sequence.

The disclosed antisense oligonucleotide can have a contiguous nucleotidesequence of 10 to 30 nucleotides in length with at least 90%complementary, such as at least 91%, such as at least 92%, such as atleast 93%, such as at least 94%, such as at least 95%, such as at least96%, such as at least 97%, such as at least 98%, or 100% complementarityto one of five exons located in the 5′-end of UBE3A-AS disclosed herein.

Oligonucleotide design refers to the pattern of nucleoside sugarmodifications in the oligonucleotide sequence. The disclosed antisenseoligonucleotide comprises sugar-modified nucleosides and may alsocomprise DNA, RNA, or arabino nucleic acid (ANA) nucleosides. In someembodiments, the oligonucleotide comprises sugar-modified nucleosidesand DNA nucleosides. In some embodiments, the oligonucleotide comprisessugar-modified nucleosides and RNA nucleosides. In some embodiments, theoligonucleotide comprises sugar-modified nucleosides and ANAnucleosides.

In some embodiments, the oligonucleotide comprises at least 1 modifiednucleoside, such as at least 2, at least 3, at least 4, at least 5, atleast 6, at least 7, at least 8, at least 9, at least 10, at least 11,at least 12, at least 13, at least 14, at least 15 or at least 16modified nucleosides. In an embodiment the oligonucleotide comprisesfrom 1 to 10 modified nucleosides, such as from 2 to 9 modifiednucleosides, such as from 3 to 8 modified nucleosides, such as from 4 to7 modified nucleosides, such as 6 or 7 modified nucleosides.

In some embodiments, the oligonucleotide comprises at least one modifiedinternucleoside linkage. In some embodiments, the internucleosidelinkages within the contiguous nucleotide sequence are phosphorothioateor boranophosphate internucleoside linkages.

In some embodiments, the disclosed antisense oligonucleotide comprisesone or more sugar modified nucleosides, such as 2′ sugar modifiednucleosides. Preferably the disclosed antisense oligonucleotidescomprise one or more LNA nucleosides or 2′ sugar modified nucleosidewherein the 2′ position is replaced by a substituent independentlyselected from the group consisting of, —F; —CF₃, —CN, —N₃, —NO, —NO₂,—O—(C₁-C₁₀ alkyl), —S—(C₁-C₁₀ alkyl), —NH—(C₁-C₁₀ alkyl), or —N(C₁-C₁₀alkyl)₂; —O—(C₂-C₁₀ alkenyl), —S—(C₂-C₁₀ alkenyl), —NH—(C₂-C₁₀ alkenyl),or —N(C₂-C₁₀ alkenyl)₂; —O—(C₂-C₁₀ alkynyl), —S—(C₂-C₁₀ alkynyl),—NH—(C₂-C₁₀ alkynyl), —N(C₂-C₁₀ alkynyl)₂, —O—(C₁-C₁₀alkylene)—O—(C₁-C₁₀ alkyl), —O—(C₁-C₁₀ alkylene)—NH—(C₁-C₁₀ alkyl),—O—(C₁-C₁₀ alkylene)—NH(C₁-C₁₀ alkyl)₂, —NH—(C₁-C₁₀ alkylene)—O—(C₁-C₁₀alkyl), and —N(C₁-C₁₀ alkyl)—(C₁-C₁₀ alkylene)—O—(C₁-C₁₀ alkyl).

In some embodiments, the disclosed oligonucleotides comprises at leastone LNA unit, such as 1, 2, 3, 4, 5, 6, 7, or 8 LNA units, such as from2 to 6 LNA units, such as from 3 to 7 LNA units, 4 to 8 LNA units or 3,4, 5, 6 or 7 LNA units. In some embodiments, all the modifiednucleosides are LNA nucleosides. In some embodiments, LNA comprises a2′-4′ biradical bridge of -L-, wherein -L- is —O—CH₂—, wherein —CH₂— isoptionally substituted. In some embodiments, LNA comprises a 2′-4′biradical bridge of -L-, wherein -L- is —O—CH₂—. In some embodiments,LNA comprises a 2′-4′ biradical bridge of -L-, wherein -L- is—O—CH(Et)—. In a further embodiment, the oligonucleotide may compriseboth beta-D-oxy-LNA, and one or more of the following LNA units:thio-LNA, amino-LNA, oxy-LNA, and/or ENA in either the beta-D or alpha-Lconfigurations or combinations thereof. In a further embodiment, all LNAcytosine units are 5-methyl-cytosine. In some embodiments, theoligonucleotide or contiguous nucleotide sequence has at least 1 LNAunit at the 5′ end and at least 2 LNA units at the 3′ end of thenucleotide sequence.

In some embodiments, the disclosed oligonucleotide is capable ofrecruiting RNase H. In some embodiments, the oligonucleotide has agapmer design or structure also referred herein merely as “Gapmer”. In agapmer structure the oligonucleotide comprises at least three distinctstructural regions a 5′-flank, a gap and a 3′-flank, F-G-F′ in ‘5−>3’orientation. In this design, flanking regions F and F′ (also termed wingregions) comprise a contiguous stretch of modified nucleosides, whichare complementary to the UBE3A-AS target nucleic acid, while the gapregion, G, comprises a contiguous stretch of nucleotides which arecapable of recruiting a nuclease, preferably an endonuclease such asRNase, for example, RNase H, when the oligonucleotide is in duplex withthe target nucleic acid. Nucleosides which are capable of recruiting anuclease, in particular RNase H, can be selected from the groupconsisting of DNA, alpha-L-oxy-LNA, 2′-Flouro-ANA and UNA. Regions F andF′, flanking the 5′ and 3′ ends of region G, preferably comprisenon-nuclease recruiting nucleosides (nucleosides with a 3′ endostructure), more preferably one or more affinity enhancing modifiednucleosides. In some embodiments, the 3′ flank comprises at least oneLNA nucleoside, preferably at least 2 LNA nucleosides. In someembodiments, the 5′ flank comprises at least one LNA nucleoside. In someembodiments both the 5′ and 3′ flanking regions comprise a LNAnucleoside. In some embodiments all the nucleosides in the flankingregions are LNA nucleosides. In other embodiments, the flanking regionsmay comprise both LNA nucleosides and other nucleosides (mixed flanks),such as DNA nucleosides and/or non-LNA modified nucleosides, such as 2′substituted nucleosides. In this case the gap is defined as a contiguoussequence of at least 5 RNase H recruiting nucleosides (nucleosides witha 2′ endo structure, preferably DNA) flanked at the 5′ and 3′ end by anaffinity enhancing modified nucleoside, preferably LNA, such asbeta-D-oxy-LNA. Consequently, the nucleosides of the 5′ flanking regionand the 3′ flanking region which are adjacent to the gap region aremodified nucleosides, preferably non-nuclease recruiting nucleosides. Inoligonucleotides with mixed flanks where the flanks comprise DNA the 5′and 3′ nucleosides are modified nucleosides.

Methods for manufacturing the disclosed oligonucleotides are known. Insome cases, the method uses phophoramidite chemistry (see for exampleCaruthers et al, 1987, Methods in Enzymology vol. 154, pages 287-313).In a further embodiment the method further comprises reacting thecontiguous nucleotide sequence with a conjugating moiety (ligand).

In some embodiments, oligonucleotide synthesis methodologies areutilized that provide control of stereochemistry at one or more modifiedinternucleoside linkages that include(s) a chiral atom. See, forexample, WO2010/064146, WO2014/012081, WO2015/107425, WO2016/079183,WO2016/079181, WO2016/096938, WO2017/194498, and WO2018/177825, whichare incorporated by reference for these methodologies.

Those skilled in the art will appreciate that useful nucleic acidsprovided by the present disclosure include those that store and/orexpress sequences of oligonucleotides described herein. In someembodiments, such nucleic acids may be or comprise vectors appropriatefor delivery into and/or replication and/or expression in a cell (e.g.,a microbial cell, for example for production and/or a mammalian cell,for example for treatment). Those skilled in the art are aware of avariety of technologies (e.g., recombinant nucleic acid technologiessuch as, for instance, that utilize one or more of amplification such asby polymerase chain reaction, cleavage such as by restriction digestion,linkage such as by ligation—whether in vitro or in vivo e.g., by gaprepair, etc.).

Also disclosed are pharmaceutical compositions comprising any of theaforementioned oligonucleotides and/or oligonucleotide conjugates and apharmaceutically acceptable diluent, carrier, salt and/or adjuvant. Apharmaceutically acceptable diluent includes phosphate-buffered saline(PBS) and pharmaceutically acceptable salts include, but are not limitedto, sodium and potassium salts. In some embodiments, the diluent isartificial cerebrospinal fluid (aCSF).

The disclosed oligonucleotides may be mixed with pharmaceuticallyacceptable active or inert substances for the preparation ofpharmaceutical compositions or formulations. Compositions and methodsfor the formulation of pharmaceutical compositions are dependent upon anumber of criteria, including, but not limited to, route ofadministration, extent of disease, or dose to be administered.

Those skilled in the art are aware of a variety of formulationstrategies useful for storage and/or administration of nucleic acidtherapeutics such as oligonucleotide therapeutics. See, for example,Pushpendra et al “Nucleic Acids as Therapeutics” in From Nucleic AcidSequences to Molecular Medicines, ed. Erdmann and Barciszewski,Springer-Verlag, 2012; Juliano “The Delivery of TherapeuticOligonucleotides” Nuc. Acids. Res. 44:6518, 2016; etc.

In some embodiments, the oligonucleotide is formulated as a prodrug. Inparticular with respect to oligonucleotide conjugates, the conjugatemoiety can be cleaved off the oligonucleotide once the prodrug isdelivered to the site of action, e.g., the target cell.

Also disclosed are methods for treating or preventing a disease,comprising administering a therapeutically or prophylactically effectiveamount of an oligonucleotide, an oligonucleotide conjugate or apharmaceutical composition disclosed herein to a subject suffering fromor susceptible to the disease.

Also disclosed is use of the disclosed oligonucleotides for themanufacture of a medicament for the treatment of a disorder as referredto herein, or for a method of the treatment of as a disorder as referredto herein.

The disclosed pharmaceutical compositions may be administered by topical(such as, to the skin, inhalation, ophthalmic or otic) or enteral (suchas, orally or through the gastrointestinal tract) or parenteral (suchas, intravenous, subcutaneous, intra-muscular, intracerebral,intracerebroventricular or intrathecal) administration. In someembodiments, the disclosed pharmaceutical compositions are administeredby a parenteral route including intravenous, intraarterial,subcutaneous, intraperitoneal or intramuscular injection or infusion,intrathecal or intracranial, e.g., intracerebral or intraventricular,administration. In some embodiments, the oligonucleotide is administeredby intracerebral or intracerebroventricular injection. In anotherembodiment the active oligonucleotide or oligonucleotide conjugate isadministered intrathecally. In some embodiments, the pharmaceuticalcomposition is administered by intracisternae magna injection.

In some embodiments, AS therapy with pharmaceutical compositionsdescribed herein is administered to subject(s) suffering from orsusceptible to AS. In some embodiments, a subject has been determined tohave genetic characteristic associated with a defect in a maternal UBE3Agene. In some embodiments, an AS-associated genetic characteristic is orcomprises a maternal deletion. In some embodiments, an AS-associatedgenetic characteristic is or comprises uniparental disomy. In someembodiments, an AS-associated genetic characteristic is or comprises aUBE3A mutation. In some embodiments, an AS-associated geneticcharacteristic is or comprises an imprinting defect.

In some embodiments, a subject has been determined to have one or moredevelopmental history and/or laboratory finding characteristics thathave been associated with AS such as, for example, one or more of:

-   -   (i) normal prenatal and birth history with normal head        circumference and absence of major birth defects;    -   (ii) feeding difficulties as a neonate and/or as an infant;    -   (iii) developmental delay evident by 6-12 months of age,        sometimes associated with truncal hypotonus;    -   (iv) unsteady limb movements and/or increased smiling;    -   (v) delayed but forward progression of development (no loss of        skills);    -   (vi) normal metabolic, hematologic and chemical laboratory        profiles;    -   (vii) structurally normal brain when assessed using MRI or CT        (may have mild cortical atrophy or dysmyelination).

Alternatively or additionally, in some embodiments, a subject has beendetermined to display one or more clinical features that areconsistently associated with AS such as, for example, one or more of:

-   -   (i) developmental delay, functionally severe    -   (ii) movement or balance disorder, usually ataxia of gait and/or        tremulous movement of limbs. In some embodiments, such movement        disorder can be mild. In some embodiments, such movement        disorder may not appear as frank ataxia but can be or involve,        for example, forward lurching, unsteadiness, clumsiness, or        quick, jerky motion;    -   (iii) behavioral uniqueness: any combination of frequent        laughter/smiling; apparent happy demeanor; easily excitable        personality, often with uplifted hand-flapping or waving        movements; hypermotoric behavior        (iv) speech impairment, such as for example absent or minimal        use of words; alternatively or additionally, receptive and        non-verbal communication skills higher than verbal ones.

Alternatively or additionally, in some embodiments, a subject has beendetermined to display one or more clinical features that are frequently(e.g., about 80% of the time) associated with AS such as, for example,one or more of:

-   -   (i) delayed, disproportionate growth in head circumference,        usually resulting in microcephaly (≤2 S.D. of normal OFC) by age        2 years. In some embodiments, microcephaly is more pronounced in        those with 15q11.2-q13 deletions;    -   (ii) seizures, onset usually <3 yrs. of age. In some        embodiments, seizure severity may decrease with age but        regardless, in some embodiments, the seizure disorder lasts        throughout adulthood.    -   (iv) abnormal EEG, with a characteristic pattern, as is known in        the art. In some embodiments, EEG abnormalities can occur in the        first 2 years of life and can precede clinical features, and may        not be correlated to clinical seizure events.

Alternatively or additionally, in some embodiments, a subject has beendetermined to display one or more clinical features that are sometimes(e.g., about 20-80% of the time) associated with AS such as, forexample, one or more of:

-   -   (i) flat occiput    -   (ii) occipital groove    -   (iii) protruding tongue    -   (iv) tongue thrusting; suck/swallowing disorders    -   (v) feeding problems and/or truncal hypotonia during infancy    -   (vi) prognathia    -   (vii) wide mouth, wide-spaced teeth    -   (viii) frequent drooling    -   (ix) excessive chewing/mouthing behaviors    -   (x) strabismus    -   (xi) hypopigmented skin, light hair and eye color, in some        embodiments determined as compared to family, and typically seen        only in deletion cases    -   (xii) hyperactive lower extremity deep tendon reflexes    -   (xiii) uplifted, flexed arm position especially during        ambulation    -   (xiv) wide-based gait with pronated or valgus-positioned ankles    -   (xv) increased sensitivity to heat    -   (xvi) abnormal sleep wake cycles and diminished need for sleep    -   (xvii) attraction to/fascination with water; fascination with        crinkly items such as certain papers and plastics    -   (xviii) abnormal food related behaviors    -   (xix) obesity (in the older child)    -   (xx) scoliosis    -   (xxi) constipation

In some embodiments, a therapeutic regimen for the treatment of AS witha nucleic acid therapeutic (e.g., an oligonucleotide therapeutic such asan ASO) as described herein is or comprises administration of one ormore doses of a pharmaceutical composition that comprises and/ordelivers an oligonucleotide as described herein.

In some embodiments, a subject to whom a provided therapeutic regimen isadministered is receiving or has received one or more other AStherapeutics including, for example, one or more other nucleic acidtherapeutics (e.g., one or more other oligonucleotides that targetUBE3A-AS). See, for example, WO2014004572A3, U.S. Pat. No. 9,617,539B2,US20170362592A1, and EP2864479B1.

In some embodiments, a subject to whom a provided therapeutic regimen isadministered has suffered or is suffering from one or more seizuresand/or is receiving or has received anti-seizure therapy. For example.In some embodiments, a subject may have received or be receiving one ormore of valproic acid, clonazepam, phenobarbital, topiramate,carbamazepine, lamotrigine, leveltiracetam, phenytoin, zonisamide,ethosuxaminde, gabapentin, felbatame, oxcarbazepine, tranxene, ACTS,nitrazapam, pregabalin, mysoline, vigabatrin, etc. In some particularembodiments, a subject may have received or be receiving one or more ofvalproic acid, clonazepam, phenobarbital, topiramate, carbamazepine,lamotrigine, and/or levetiracetam.

Alternatively or additionally, in some embodiments, a subject may havereceived or be receiving dietary therapy such as, for example, aketogenic diet, low glycemic index therapy, etc.

Still further alternatively or additionally, in some embodiments, asubject may have received or be receiving treatment with a vagal nervestimulator.

As will be apparent to those skilled in the art reading the presentdisclosure, provided methods of treatment involve administering one orboth of an oligonucleotide as described herein and an additional therapy(e.g., an alternative oligonucleotide and/or anti-epileptic therapyand/or one or more other therapeutic interventions), so that the subjectreceives combination therapy (e.g., is simultaneously exposed thereto,for example via overlapping dosing etc.). Also disclosed is the use ofan oligonucleotide disclosed herein for the manufacture of a medicamentwherein the medicament is in a dosage form for intrathecaladministration.

Also disclosed is the use of an oligonucleotide disclosed herein for themanufacture of a medicament wherein the medicament is in a dosage formfor intracerebral or intraventricular administration.

Also disclosed is the use of an oligonucleotide disclosed herein for themanufacture of a medicament wherein the medicament is in a dosage formfor intracerebroventricular administration.

In some embodiments the oligonucleotide disclosed herein is for use in acombination treatment with another therapeutic agent. The therapeuticagent can for example be anticonvulsant medication.

A number of embodiments of the invention have been described.Nevertheless, it will be understood that various modifications may bemade without departing from the spirit and scope of the invention.Accordingly, other embodiments are within the scope of the followingclaims.

EXAMPLES Example 1

Results

RNA-sequencing analysis of mouse and human CNS identified a regionbelieved to be important for the stability and/or transcription ofUBE3A-AS. Further analysis of the region showed low levels of sequenceconservation between mouse and human (FIGS. 1A-1D).

Based on these findings, mouse-specific ASOs were designed to target aspecific region in the Ube3a-AS transcript (Table 6 and FIG. 2A). Totest whether ASOs targeting this region reactivate expression of thepaternal Ube3a allele, primary hippocampal neuronal cultures weregenerated from the Ube3aYFP reporter mouse model (Ube3a+/YFP; FIG. 2B)and treated at 7 days in vitro (DIV) with a control ASO [ASO-C (10 μM,n=3)], three ASOs targeting Ube3a-AS [ASO-1.1, ASO-1.2, ASO-3.1 (1 μM, 5μM, and 15 μM, n=3)], and ASO-B (1 μM, 5 μM, and 15 μM, n=3)]. As apositive control, neurons were also treated with Topotecan [Topo (300nM, n=3)] and a negative vehicle control [Veh (1%, n=3); FIG. 2 C].Three days post-treatment (10 DIV), immunofluorescent imaging was usedto quantify paternal Ube3aYFP protein levels in individual cells.Compared to controls (ASO-C and Veh), each treatment substantiallyincreased paternal Ube3aYFP protein levels, with similar levels achievedin ASO-1.1 (15 μM), ASO-3.1 (15 μM), and Topotecan treatments (FIGS. 2Dand 2E).

Human-specific ASOs were then designed to target this region, whichincluded four ASOs targeting non-polymorphic regions in human andregions conserved (100%) with macaque (Rhesus and Cynomolgus) (Table 7and FIG. 3A). Human induced pluripotent stem cell (iPSC) neuralprecursor cells were differentiated into GABAergic neurons for 14 DIVand then treated with a control ASO [ASO-C (10 μM, n=3)], Topotecan[Topo (1 μM, n=2)], and six ASOs targeting UBE3A-AS [ASO-1, ASO-2,ASO-3, ASO-4, ASO-5, and ASO-6 (10 μM, n=3)]. Additionally, an ASOtargeting an intronic region downstream of SNORD109B was included(ASO-7). Six days post-treatment (20 DIV), RNA was isolated from theneurons and the steady state RNA levels of UBE3A-AS and UBE3A wereestimated relative to the control treatment (FIG. 3B). With theexception of ASO-7, each ASO significantly decreased UBE3A-AS RNAlevels, with ASO-2 and ASO-4 having the largest effect (Table 8 and FIG.3C). UBE3A RNA levels also increased after treatment with each ASO (FIG.3D).

The potency of ASO-4 was further examined given its effect on UBE3A-AS

RNA levels. GABAergic iPSC-derived neurons were treated at 14 DIV with a10-point % log dose response curve of ASO-4 and Topotecan, as a positivecontrol and for comparisons between treatment [1 nM, 3 nM, 10 nM, 30 nM,100 nM, 300 nM, 1 μM, 3 μM, 10 μM, and 30 μM (ASO-4, n=6; Topotecan,n=2)]. At 20 DIV, the steady state RNA levels of UBE3A-AS were measuredand dose response curves fitted to estimate the IC₅₀ and E_(max) (i.e.,maximum UBE3A-AS inhibition) (Table 9 and FIG. 4A). The dose responsecurves of ASO-4 and Topotecan were significantly different (Parallelismtest: F_((3,145))=11.2, p<0.0001), thus the relative potencies were notestimated. An equivalence test indicated that the IC₅₀ and E_(max) ofASO-4 and Topotecan were not equivalent [ASO-4/Topotecan IC₅₀ ratio:=1.2(Lower confidence limit=1.1; Upper confidence limit=1.3); E_(max)ratio=-4.1 (Lower confidence limit=−12.9; Upper confidence limit=4.8)].

The effects of ASO-4 and Topotecan were then examined on the SNORD116,IPW, SNORD115, and SNORD109A RNAs, which are located upstream of theASO-4 target region (see FIG. 1A). With the exception of SNORD116, ASO-4had a significant effect on the RNA levels of IPW, SNORD115, andSNORD109A/B but not in a dose dependent manner. In contrast, Topotecanhad a significant effect on SNORD116, IPW, SNORD115, and SNORD109A/B RNAlevels that was dose dependent (Table 10 and FIGS. 4B-4E). Both ASO-4and Topotecan increased total UBE3A RNA levels in a dose-dependentmanner, except for Topotecan at higher concentrations (3 μM, 10 μM, and30 μM; FIG. 4F).

The potency of ASO-4 was further examined in iPSC-derived neurons at alater time point in differentiation. GABAergic iPSC-derived neurons weretreated at 59 DIV with a control ASO [ASO-C, 10 μM (n=3)] and ASO-4 [1μM, 5 μM, and 10 μM (n=3)], and the steady state RNA levels of UBE3A-ASand UBE3A were measured as described above (FIG. 4G). Unlike neuronstreated with ASO-4 at an earlier time point, the RNA levels of UBE3A andUBE3A-AS were highly inversely correlated (FIGS. 4H and 4I). Forexample, the effect of ASO-4 (10 μM) on UBE3A-AS RNA levels was similarbetween neurons treated at 14 and 59 DIV [20 DIV: UBE3A-AS: ↓87% (95%confidence intervals (CI): 80 to 95%); 65 DIV: ↓81% (95% Cl: 74 to88%)], whereas the effect of ASO-4 on UBE3A RNA levels was substantiallylarger in neurons treated at 59 DIV [20 DIV: ↑30% (95% Cl: 16 to 44%);65 DIV: ↑86% (95% Cl: 59% to 113%)].

Additional ASOs targeting the 5′-end of UBE3A-AS were then designed tooptimize the target sequences of ASO-4 (ASO-4.1, ASO-4.2, ASO-4.3, andASO-4.4) as well as two other target regions, ASO-3 (ASO-3.1 andASO-3.2) and ASO-6 (ASO-6.1) (Table 11). Additionally, ASO-4 wasmanufactured at two different vendors for comparative purposes (ASO-4.S,Sigma; ASO-4.1, Integrated DNA Technologies). Human iPSC-derived neurons(GABAergic) were treated at 14 DIV with a 5-point ½ log dose curve ofASO-3.1, ASO-3.2, ASO-4.S, ASO-4.1, ASO-4.1, ASO-4.2, ASO-4.3, ASO-4.4,and ASO-6.1 [30 nM, 100 nM, 300 nM, 1 μM (n=6)]. At 20 DIV, the IC₅₀ andE_(max) of each ASO was estimated as described above (FIG. 5A-B andTable 12). The dose response curves were similar among ASOs (Parallelismtest: F_((16,513))=1.6, p=0.06), with ASO-4 and ASO-6.1 having thehighest relative potency (Table 13). No significant difference wasobserved between ASO-4.S and ASO-4.1.

The potency of ASO-4 and ASO-6.1 was further examined in iPSC-derivedneurons at a later time point in differentiation. GABAergic iPSC-derivedneurons were treated at 29 DIV with a 10-point ½ log dose response curveof ASO-4 and ASO-6.1 [1 nM, 3 nM, 10 nM, 30 nM, 100 nM, 300 nM, 1 μM, 3μM, 10 μM, and 30 μM (n=3)]. At 35 DIV, the IC₅₀ and E_(max) of each ASOwas estimated as described above (FIG. 5 C-D and Table 14). The doseresponse curves of ASO-4 and ASO-6.1 were not similar (Parallelism test:F_((3,172))=22.7, p<0.0001). An equivalence test indicated that ASO-4and ASO-6.1 had equivalent potencies but different E_(max) values[ASO-6.1/ASO-4 ratio: IC₅₀=1.03 (Lower confidence limit=1.0; Upperconfidence limit=1.1); E_(max)=−1.3 (Lower confidence limit=−2.6; Upperconfidence limit=−0.08)], with ASO-6.1 having the largest inhibition ofUBE3A-AS levels. The effect of ASO-4 and ASO-6.1 on UBE3A RNA levels wassimilar, with each treatment increasing RNA levels in dose dependentmanner (FIG. 5D).

ASO-4 and ASO-6.1 were also examined in glutamatergic iPSC-derivedneurons. Glutamatergic iPSC-derived neurons were treated at 14 DIV witha 10-point ½ log dose response curve of ASO-4 and ASO-6.1 [1 nM, 3 nM,10 nM, 30 nM, 100 nM, 300 nM, 1 μM, 3 μM, 10 μM, and 30 μM (n=3)]. At 20DIV, the IC₅₀ and E_(max) of each ASO was estimated as described above(FIG. 5E-F and Table 15). The dose response curves of ASO-4 and ASO-6.1were similar and not significantly different (Parallelism test:F_((3,165))=1.9, p=0.1), with ASO-6.1 having the highest relativepotency (Table 16). As expected, ASO-4 and ASO-6.1 increased UBE3A

RNA levels in a dose dependent manner (FIG. 5F); however, there was ahigh degree of variation for each concentration that was notattributable to treatment (R²=0.17).

CONCLUSIONS

Towards developing a therapy for AS, experiments were conducted todetermine whether ASOs targeting a specific region inhibitUbe3a-ASIUBE3A-AS and reactivate expression of the paternal Ube3a/UBE3Aallele in mouse and human neurons. Altogether, findings show that ASOstargeting this region in mouse and human neurons have potent antisenseactivity and reverse imprinting of Ube3a/UBE3A.

Two of the three ASOs (ASO-1.1 and ASO-3.1) targeting Ube3a-ASreactivated expression of the paternal Ube3a allele in mouse neurons toa level similar to that achieved by the optimal concentration ofTopotecan (300 nM).

Likewise, each of the human-specific ASOs significantly reduced thesteady state RNA levels of UBE3A-AS in human iPSC-derived neurons, withhigher concentrations of ASO-4 and ASO-6.1 almost completely abolishingexpression of UBE3A-AS. Given that ASO-4 and ASO-6.1 target regions thatare 100% conserved between human and macaque, the efficacy of these ASOscan be examined in vivo in either Cynomolgus or Rhesus macaque. UnlikeTopotecan, ASO-4 has a small, if any, effect on the upstream SNORD116,IPW, SNORD115, or SNORD109A/B RNAs, consistent with the notion that theASO terminates transcription at or downstream of the target region.

Low concentrations (3 nM) of ASO-4 and ASO-6.1 significantly reducedUBE3A-AS RNA levels; however, higher concentrations (≥100 nM) of ASOwere necessary to increase UBE3A RNA levels. This may reflect a certainthreshold required for UBE3A-AS to inhibit transcription of UBE3A, or alag between the time that inactivation of UBE3A-AS leads to reactivationof paternal UBE3A, or the sensitivity of the assay used to quantifyUBE3A RNA levels.

Collectively, findings suggest that ASOs targeting a candidate region inUBE3A-AS almost completely abolishes imprinting of UBE3A in neurons andreveals at least two ASOs for future clinical development.

Derivatives of ASO-4 and ASO-6.1 that are comprised of different RNAmodifications [2′-hydroxymethyl (2′-OMe), 2′-methoxy-ethyl 2′-MOE, andlocked nucleic acid (LNA)] and backbones [phosphorothioate (PS) andphosphodiester (PO)] have also been designed (Table 17).

TABLE 6 Mouse Ube3a-AS Oligonucleotides RNA RNA DNA Modifi- Back- Back-Design ASO cation bone bone (5′-3′) Sequence SEQ ID ASO-B 2′-OMe PS PS5-10-5 C^(O)*C^(O)*A^(O)*G^(O)*C^(O)*c*t*t*g*t*t*g*g*a*t*A^(O)*U^(O)*SEQ ID NO: 358 C^(O)*A^(O)*U^(O) ASO-1.1 2′-OMe PS PS 5-10-5C^(O)*C^(O)*A^(O)*C^(O)*A^(O)*t*t*t*c*c*t*c*t*c*a*U^(O)*G^(O)*SEQ ID NO: 359 G^(O)*A^(O)*A^(O) ASO-1.2 2′-OMe PS PS 5-10-5G^(O)*A^(O)*G^(O)*U^(O)*G^(O)*t*t*t*g*c*a*a*a*c*c*A^(O)*A^(O)*SEQ ID NO: 360 U^(O)*G^(O)*U^(O) ASO-3.1 2′-OMe PS PS 5-10-5U^(O)*G^(O)*U^(O)*U^(O)*U^(O)*c*t*t*t*g*g*t*g*a*t*U^(O)*C^(O)*SEQ ID NO: 361 U^(O)*G^(O)*C^(O) Capital letter, RNA; lower-case letter,DNA; O, 2′-OMe; PS & *, phosphorothioate

TABLE 7 Human UBE3A-AS Oligonucleotides RNA RNA DNA Modifi- Back- Back-Design ASO cation bone bone (5′-3′) Sequence SEQ ID ASO-1 2′-OMe PS PS5-10-5 U^(O)*A^(O)*G^(O)*A^(O)*G^(O)*g*t*g*a*a*g*g*c*c*a*G^(O)*G^(O)*SEQ ID NO: 362 C^(O)*A^(O)*C^(O) ASO-2 2′-OMe PS PS 5-10-5G^(O)*U^(O)*A^(O)*C^(O)*U^(O)*c*t*t*c*c*t*c*a*g*t*C^(O)*A^(O)*SEQ ID NO: 363 U^(O)*C^(O)*C^(O) ASO-3^(C) 2′-OMe PS PS 5-10-5U^(O)*G^(O)*U^(O)*C^(O)*A^(O)*g*t*t*t*c*t*c*c*c*t*G^(O)*A^(O)*SEQ ID NO: 364 A^(O)*C^(O)*A^(O) ASO-4^(C) 2′-OMe PS PS 5-10-5U^(O)*A^(O)*G^(O)*A^(O)*A^(O)*t*g*g*c*a*c*a*t*c*t*C^(O)*U^(O)*SEQ ID NO: 365 U^(O)*G^(O)*G^(O) ASO-5^(C) 2′-OMe PS PS 5-10-5G^(O)*U^(O)*U^(O)*U^(O)*U^(O)*c*t*t*c*c*t*c*c*a*c*A^(O)*G^(O)*SEQ ID NO: 366 U^(O)*C^(O)*U^(O) ASO-6^(C) 2′-OMe PS PS 5-10-5C^(O)*U^(O)*G^(O)*G^(O)*U^(O)*g*t*c*a*a*c*a*a*g*c*C^(O)*A^(O)*SEQ ID NO: 367 A^(O)*A^(O)*G^(O) Abbreviations: ^(C), conserved withmacaque & non-polymorphic; capital letter, RNA nucleotide; lower-caseletter, DNAnucleotic e; ^(O), 2′-OMe; PS & *, phosphorothioate

TABLE 8 Analysis of Human ASOs on UBE3A-AS and UBE3A RNA levels ASO 1ASO 2 Difference Lower CI Upper CI Adj. P UBE3A-AS ASO-C ASO-2 0.89 0.820.97 <.0001 ASO-R ASO-2 0.87 0.80 0.95 <.0001 ASO-C ASO-4 0.87 0.80 0.95<.0001 ASO-R ASO-4 0.85 0.78 0.93 <.0001 ASO-C ASO-6 0.83 0.75 0.90<.0001 ASO-R ASO-6 0.81 0.74 0.89 <.0001 ASO-C ASO-3 0.79 0.71 0.86<.0001 ASO-R ASO-3 0.77 0.70 0.85 <.0001 ASO-C ASO-5 0.71 0.63 0.78<.0001 ASO-R ASO-5 0.69 0.62 0.77 <.0001 ASO-C Topo 0.66 0.59 0.73<.0001 ASO-R Topo 0.64 0.57 0.72 <.0001 ASO-C ASO-1 0.51 0.43 0.58<.0001 ASO-R ASO-1 0.49 0.41 0.56 <.0001 ASO-1 ASO-2 0.38 0.31 0.46<.0001 ASO-1 ASO-4 0.36 0.29 0.44 <.0001 ASO-1 ASO-6 0.32 0.25 0.40<.0001 ASO-1 ASO-3 0.28 0.21 0.36 <.0001 Topo ASO-2 0.23 0.16 0.31<.0001 Topo ASO-4 0.21 0.14 0.29 <.0001 ASO-1 ASO-5 0.20 0.13 0.28<.0001 ASO-5 ASO-2 0.18 0.11 0.26 <.0001 Topo ASO-6 0.17 0.10 0.240.0002 ASO-5 ASO-4 0.16 0.09 0.24 0.0003 ASO-1 Topo 0.15 0.08 0.230.0004 Topo ASO-3 0.13 0.06 0.20 0.0018 ASO-5 ASO-6 0.12 0.04 0.200.0035 ASO-3 ASO-2 0.10 0.03 0.18 0.0111 ASO-3 ASO-4 0.08 0.01 0.160.0360 ASO-5 ASO-3 0.08 0.00 0.15 0.0381 ASO-6 ASO-2 0.06 −0.01 0.140.11 Topo ASO-5 0.05 −0.02 0.13 0.18 ASO-6 ASO-4 0.04 −0.03 0.12 0.27ASO-3 ASO-6 0.04 −0.03 0.12 0.28 ASO-4 ASO-2 0.02 −0.06 0.09 0.58 ASO-CASO-R 0.02 −0.06 0.09 0.64 UBE3A ASO-4 ASO-C 0.30 0.16 0.44 0.0004 ASO-4ASO-R 0.29 0.14 0.45 0.001 ASO-2 ASO-C 0.21 0.09 0.34 0.002 ASO-2 ASO-R0.21 0.07 0.35 0.006 ASO-1 ASO-C 0.18 0.06 0.31 0.007 Topo ASO-C 0.180.04 0.32 0.01 ASO-1 ASO-R 0.18 0.04 0.32 0.02 Topo ASO-R 0.18 0.03 0.330.02 ASO-4 ASO-3 0.17 0.03 0.31 0.02 ASO-5 ASO-C 0.16 0.04 0.29 0.01ASO-6 ASO-C 0.16 0.04 0.29 0.01 ASO-5 ASO-R 0.16 0.02 0.30 0.03 ASO-6ASO-R 0.16 0.02 0.30 0.03 ASO-4 ASO-6 0.13 −0.007 0.27 0.06 ASO-4 ASO-50.13 −0.007 0.27 0.06 ASO-3 ASO-C 0.13 0.00 0.26 0.04 ASO-3 ASO-R 0.13−0.015 0.27 0.08 ASO-4 Topo 0.11 −0.04 0.27 0.1 ASO-4 ASO-1 0.11 −0.030.25 0.1 ASO-2 ASO-3 0.08 −0.04 0.21 0.2 ASO-4 ASO-2 0.08 −0.06 0.22 0.2ASO-1 ASO-3 0.05 −0.07 0.18 0.4 Topo ASO-3 0.05 −0.09 0.19 0.4 ASO-2ASO-6 0.05 −0.08 0.18 0.4 ASO-2 ASO-5 0.05 −0.08 0.17 0.4 ASO-5 ASO-30.03 −0.09 0.16 0.6 ASO-6 ASO-3 0.03 −0.09 0.16 0.6 ASO-2 Topo 0.03 −0.10.17 0.7 ASO-2 ASO-1 0.03 −0.01 0.16 0.6 ASO-1 ASO-6 0.02 −0.1 0.15 0.7Topo ASO-6 0.02 −0.1 0.16 0.8 ASO-1 ASO-5 0.02 −0.1 0.15 0.7 Topo ASO-50.02 −0.1 0.16 0.8 ASO-R ASO-C 0.00 −0.1 0.14 0.9 ASO-5 ASO-6 0.00 −0.10.13 0.9 ASO-1 Topo 0.00 −0.1 0.14 1.00 Abbreviations: ASO-C,ASO-control; Topo, Topotecan; Adj., Adjusted; CI, 95% confidenceinterval

TABLE 9 IC₅₀ and E_(max) of ASO-4 and Topotecan Treatment IC₅₀ Estimate(M) IC₅₀ 95% CI (M) E_(max) Estimate E_(max) 95% CI 30 μM (Mean) ASO-46.13E−07 3.47E−07 1.08E−06 −0.06 −0.23 0.10 0.09 Topo 3.37E−08 1.85E−086.14E−08  0.26  0.20 0.32 0.21 Full model parameter estimates from4-parameter logistic regression model (Hill). IC₅₀ and confidenceintervals represent molar concentration. E_(max) and 30 uM valuesrepresent normalized UBE3A-AS RNA levels relative to vehicle.

TABLE 10 Analysis of ASO-4 and Topotecan on UBE3A, SNORD116, SNORD115,SNORD109A/B, and IPW RNA Levels Treatment RNA DF DFDen F Ratio FDR ASO-4UBE3A 9 108 16.5 <0.0001 SNORD109A/B 9 104.9 2.6 0.01 SNORD115 9 108 4.00.0002 SNORD116 9 108 1.74 0.09 IPW 9 108 4.1 0.0002 Topotecan UBE3A 929 5.6 0.0002 SNORD109A/B 9 29 28.2 <0.0001 SNORD115 9 29 4.60 0.001SNORD116 9 29 7.12 <0.0001 IPW 9 29 49.8 <0.0001 Least squares linearregression. Abbreviations: DF, degrees of freedom; DFDen, degrees offreedom density

TABLE 11 Optimized Human UBE3A-AS Antisense Oligonucleotides RNA RNA DNAModifi- Back- Back- Design ASO cation bone bone (5′-3′) Sequence SEQ IDASO-3.1^(C) 2′-OMe PS PS 4-10-5G^(O)*U^(O)*U^(O)*G^(O)*a*g*t*g*g*t*g*t*c*a*G^(O)*U^(O)*U^(O)*U^(O)*C^(O)SEQ ID NO: 368 ASO-3.2^(C) 2′-OMe PS PS 4-10-4U^(O)*U^(O)*G^(O)*A^(O)*g*t*g*g*t*g*t*c*a*g*U^(O)*U^(O)*U^(O)*C^(O)SEQ ID NO: 369 ASO-6.1^(C) 2′-OMe PS PS 4-10-4C^(O)*U^(O)*G^(O)*G^(O)*t*g*t*c*a*a*c*a*a*g*C^(O)*C^(O)*A^(O)*A^(O)SEQ ID NO: 370 ASO-4.1^(C) 2′-OMe PS PS 5-10-5A^(O)*U^(O)*A^(O)*G^(O)*A^(O)*a*t*g*g*c*a*c*a*t*C*U^(O)*C^(O)*U^(O)*SEQ ID NO: 371 U^(O)*G^(O) ASO-4.2^(C) 2′-OMe PS PS 4-10-5A^(O)*G^(O)*A^(O)*A^(O)*t*g*g*c*a*c*a*t*c*t*C^(O)*U^(O)*U^(O)*G^(O)*G^(O)SEQ ID NO: 372 ASO-4.3^(C) 2′-OMe PS PS 4-10-5U^(O)*A^(O)*G^(O)*A^(O)*a*t*g*g*c*a*c*a*t*c*U^(O)*C^(O)*U^(O)*U^(O)*G^(O)SEQ ID NO: 373 ASO-4.4^(C) 2′-OMe PS PS 4-10-4A^(O)*G^(O)*A^(O)*A^(O)*t*g*g*c*a*c*a*t*c*t*C^(O)*U^(O)*U^(O)*G^(O)SEQ ID NO: 374 ^(C), conserved with macaque & non-polymorphic; capitalletter, RNA nucleotide; lower-case letter, DNA nucleotide; O, 2′-OMe; PS& *, phosphorothioate

TABLE 12 IC₅₀ and E_(max) of Optimized ASO Target Sequences Group IC₅₀Estimate IC₅₀ 95% CI (M) 3 μM (Mean) 6.1 5.20E−07 3.33E−07 8.11E−07 0.234.0 1.06E−06 9.31E−07 1.21E−06 0.29 4.2 1.08E−06 8.62E−07 1.35E−06 0.313.2 1.88E−06 1.39E−06 2.56E−06 0.44 4.3 2.03E−06 1.67E−06 2.47E−06 0.404.4 2.11E−06 1.73E−06 2.59E−06 0.44 4.1 2.27E−06 1.92E−06 2.68E−06 0.423.1 2.98E−06 2.45E−06 3.62E−06 0.51 Full model parameter estimates from3-parameter logistic regression model. IC₅₀ and confidence intervalsrepresent molar concentration. E_(max) (3 uM) values representnormalized UBE3A-AS RNA levels relative to vehicle.

TABLE 13 Relative Potency of Optimized ASOs ASO IC₅₀ (M) RelativePotency Std. Error ASO 3.1 2.81E−06 0.53 0.059 ASO 3.2 1.85E−06 0.810.086 ASO 4.1 2.25E−06 0.66 0.072 ASO 4.2 1.24E−06 1.21 0.13 ASO 4.31.96E−06 0.76 0.081 ASO 4.4 2.04E−06 0.73 0.079 ASO 6.1 7.20E−07 2.070.21 ASO 4.1 8.28E−07 1.80 0.19 ASO 4.S 1.49E−06 1 0 Parallel modelparameter estimates from 3-parameter logistic regression model. Potencyrepresents molar concentration. Abbreviations: M, molar; Std. Error,standard error of mean.

TABLE 14 IC₅₀ and E_(max) of ASO-4 and ASO-6.1 in GABAergic iPSC NeuronsASO IC₅₀ Estimate IC₅₀ 95% CI (M) E_(max) Estimate E_(max) 95% CI 30 μM(Mean) ASO-4 7.77E−07 6.86E−07 8.79E−07  0.08  0.05 0.11 0.11 ASO-6.15.17E−07 3.41E−07 7.82E−07 −0.11 −0.22 0.01 0.06 Full model parameterestimates from 4-parameter logistic regression model (Hill). IC₅₀ andconfidence intervals represent molar concentration. E_(max) and 30 uMvalues represent normalized UBE3A-AS RNA levels relative to vehicle.

TABLE 15 IC₅₀ and E_(max) of ASO-4 and ASO-6.1 in Glutamatergic iPSCNeurons ASO IC₅₀ Estimate IC₅₀ 95% CI (M) E_(max) Estimate E_(max) 95%CI 30 μM (Mean) ASO-4 1.21E−04 1.12E−13 1.32E+05 −1.45 −9.01 6.12 0.17ASO-6.1 2.44E−07 2.39E−08 2.50E−06 −0.27 −1.24 0.70 0.04 Full modelparameter estimates from 4-parameter logistic regression model (Hill).IC₅₀ and confidence intervals represent molar concentration. E_(max) and30 uM values represent normalized UBE3A-AS RNA levels relative tovehicle.

TABLE 16 Relative Potency of ASO-4 and ASO-6.1 in Glutamatergic NeuronsASO IC₅₀ (M) Relative Potency Std. Error ASO-4 3.06E−06 1 0 ASO-6.1 7.8E−07 3.89 0.72 Parallel model parameter estimates from 4 Parameterlogistic regression model. Abbreviations: M, molar

TABLE 17 Derivatives of ASO-4 and ASO-6.1 RNA Back- PO Design ASO Mod.bone linkages (5′-3′) Sequence (5′-3′) SEQ ID ASO-4.0.PS.O OMe PS 05-10-5U^(O)*A^(O)*G^(O)*A^(O)*A^(O)*t*g*g*c*a*c*a*t*c*t*C^(O)*U^(O)*U^(O)*G^(O)*G^(O)SEQ ID NO: 375 ASO-4.0.PO-1.O OMe PS/PO 2 5-10-5U^(O)*A°*G^(O)*A^(O)*A^(O)-t*g*g*c*a*c*a*t*c*t-C^(O)*U^(O)*U^(O)*G^(O)*G^(O)SEQ ID NO: 376 ASO-4.0.PO-2.O OMe PS/PO 0 5-10-5U^(O)*A^(O)-G^(O)*A^(O)-A^(O)*t-g*g-c*a-c*a-t*c-t*C^(O)-U^(O)*U^(O)-G^(O)*G^(O)SEQ ID NO: 377 ASO-4.0.PS.M MOE PS 0 5-10-5T^(M)*A^(M)*G^(M)*A^(M)*A^(M)*t*g*g*c*a*c*a*t*c*t*5mC^(M)*T^(M)*T^(M)*G^(M)*G^(M)SEQ ID NO: 378 ASO-4.0.PO-1.M MOE PS/PO 2 5-10-5T^(M)*A^(M)*G^(M)*A^(M)*A^(M)-t*g*g*c*a*c*a*t*c*t-5mC^(M)*T^(M)*T^(M)*G^(M)*G^(M)SEQ ID NO: 379 ASO-4.0.PO-2.M MOE PS/PO 9 5-10-5T^(M)*A^(M)-G^(M)*A^(M)-A^(M)*t-g*g-c*a-c*a-t*c-t*5mC^(M)-T^(M)*T^(M)-G^(M)*G^(M)SEQ ID NO: 380 ASO-4.4.PS.L LNA PS 0 3-11-4A^(L)*G^(L)*A^(L)*a*t*g*g*c*a*c*a*t*c*t*5mC^(L)-*T^(L)-*T^(L)*G^(L)SEQ ID NO: 381 ASO-4.4.PO-1.L LNA PS/PO 2 3-11-4A^(L)*G^(L)*A^(L)a*t*g*g*c*a*c*a*t*c*t-5mC^(L)-*T^(L)-*T^(L)G^(L)SEQ ID NO: 382 ASO-4.4.PO-2.L LNA PS/PO 8 3-11-4A^(L)*G^(L)-A^(L)*a-t*g-g*c-a*c-a*t-c*t-5mC^(L)*T^(L)-T^(L)*G^(L)SEQ ID NO: 383 ASO-6.1.PS.O OMe PS 0 4-10-4C^(O)*U^(O)*G^(O)*G^(O)*t*g*t*c*a*a*c*a*a*g*C^(O)*C^(O)*A^(O)*A^(O)SEQ ID NO: 384 ASO-6.1.PO-1.O OMe PS/PO 2 4-10-4C^(O)*U^(O)*G^(O)*G^(O)-t*g*t*c*a*a*c*a*a*g-C^(O)*C^(O)*A^(O)*A^(O)SEQ ID NO: 385 ASO-6.1.PO-2.O OMe PS/PO 8 4-10-4C^(O)*U^(O)-G^(O)*G^(O)t*g-t*c-a*a-c*a-a*g-C^(O)*C^(O)A^(O)*A^(O)SEQ ID NO: 386 ASO-6.1.PS.M MOE PS 0 4-10-45mC^(M)*T^(M)*G^(M)*G^(M)*t*g*t*c*a*a*c*a*a*g*5mC^(M)*5mC^(M)*A^(M)*A^(M)SEQ ID NO: 387 ASO-6.1.PO-1.M MOE PS/PO 2 4-10-45mC^(M)*T^(M)*G^(M)*G^(M)-t*g*t*c*a*a*c*a*a*g-5mC^(M)*5mC^(M)*A^(M)*A^(M)SEQ ID NO: 388 ASO-6.1.PO-2.M MOE PS/PO 8 4-10-45mC^(M)*T^(M)-G^(M)*G^(M)-t*g-t*c-a*a-c*a-a*g-5mC^(M)*5mC^(M)-A^(M)*A^(M)SEQ ID NO: 389 ASO-6.1.PS.L LNA PS 0 3-10-4T^(L)*G^(L)*G^(L)*t*g*t*c*a*a*c*a*a*g*5mC^(L)*5mC^(L)*A^(L)*A^(L)SEQ ID NO: 390 ASO-6.1.PO-1.L LNA PS/PO 2 3-10-4T^(L)*G^(L)*G^(L)-t*g*t*c*a*a*c*a*a*g-5mC^(L)*5mC^(L)*A^(L)*A^(L)SEQ ID NO: 391 ASO-6.1.PO-2.L LNA PS/PO 8 3-10-4T^(L)*G^(L)-G^(L)*t-g*t-c*a-a*c-a*a-g*5mC^(L)-5mC^(L)-A^(L)*A^(L)SEQ ID NO: 392 Capital letter, RNA; lower-case letter, DNA. 5mC,5-methylcytosine. Superscript: O, 2′-OMe; M, 2′-MOE; L, LNA. PS & *, phosphorothioate; PO & -, phosphodiesterMaterials and MethodsAntisense Oligonucleotide Design

Antisense oligonucleotides (ASOs) were designed using Soligo (Softwarefor Statistical Folding of Nucleic Acids and Studies of RegulatoryRNAs). Briefly, candidate ASOs (20-18 mer) with the lowest binding sitedisruption energy and free binding energy were identified for eachtarget sequence and then inspected for motifs with increasedeffectiveness. ASOs were further filtered based on accessibility withinpredicted lowest free energy centroid secondary structure of targetsequence generated by Soligo. In some instances, secondary structuremodels were compared using lowest free energy structures generated byRNAfold and Mfold.

Human ASOs were filtered using the following criteria: 1) targetsequence was polymorphic [dbSNP138, dbSNP150, and 1000 Genomes Phase 3Integrated Variant Calls (SNV, INDEL, and SV)]; 2) target sequence wasnot 100% conserved with Rhesus and Cynomolgus macaque; 3) targetsequence was located upstream of retained Snord115/SNORD115 snoRNA (perexon). Remaining ASOs were then ranked by free energy (<=−8 kcal/mol),average unpaired probability for target site nucleotides, binding sitedisruption energy (low>high), location within secondary structure(Ensembl Centroid), and presence/absence of sequence motifs associatedwith high/low effectiveness.

Mouse Primary Hippocampal Neurons

Primary cultures of hippocampal neurons were generated from P0-P1 pups(Ube3a^(m+/p+) and Ube3a^(m+/pYFP)) by crossing Ube3a^(m+/pYFP) maleswith wild-type C57BL/6J females. Genotypes were determined using methodsdescribed previously. Briefly, hippocampal neurons were cultured inNeurobasal A medium (Invitrogen, San Diego, Calif.) supplemented withB27 (Invitrogen) and penicillin/streptomycin (Invitrogen) on 96-welloptical bottom plates coated with poly-D-Lysine (152028, Thermo FisherScientific) and laminin (23017-01, Thermo Fisher Scientific). Cultureswere maintained at 37° C. in 5% CO₂ until use.

Mouse Neuron Imaging

Mouse primary hippocampal neurons were fixed at 10 DIV (3 days posttreatment) with 4% paraformaldehyde. The cultures were then washed twicewith 1× PBS, fixed in 4% paraformaldehyde in PBS for 15 min, and thenwashed three times in 1× PBS. The cells were blocked in 0.3% Triton-X100in PBS (T-PBS) plus 5% goat or donkey serum for 1-2 hr at roomtemperature with gentle agitation. Cells were incubated with anti-GFP[Novus Biologicals, NB 600-308 (rabbit)] and anti-NeuN (Millipore,05-557 (mouse)] antibodies for 24 hr at 4° C. with gentle agitation.Cells were washed 3 times in 0.1% Tween 20 1× PBS for 15 min each andthen incubated with anti-rabbit 488 (Jackson ImmunoResearch,111-545-144) and anti-mouse Cy3 (Jackson ImmunoResearch, 115-165-166)secondary antibodies for 24 hr at 4° C. in the dark. Cells were thenwashed 4 times in 0.1% Tween 20 1× PBS for 15 min each. Nuclei werelabeled using Hoechst stain (Thermo Fisher Scientific) at a dilution of1:1000 in the third wash.

Plates were imaged using the Cytation 5 and Gen5 Image+software (BioTek,Winooski, Vt.). Briefly, a 4× inverted objective was used to generatemontage images of each well by acquiring 5×4 autofocused images withoverlapping tiles for automatic image stitching. The filters used wereDAPI (377,477), GFP (469, 525), and RFP (531, 593). Exposure time andgain were adjusted for each plate using the negative and positivecontrols. Auto-focus was performed on nuclei (Hoechst stain, DAPI) foreach well, with the same focal height used for the GFP and RFP filters.Images were stitched together by Gen5 Image+software.

Single cell image analysis was performed using IN Cell Developer 6.0 (GEHealthcare Life Sciences, Pittsburgh, Pa.). Briefly, individual trackmasks were generated for either nuclei (Hoechst stain, DAPI) or matureneurons (NeuN, RFP) by optimizing inclusion and exclusion parametersbased on size and intensity of randomly selected cells in the acquiredimages. The mean and median intensity values of GFP were then acquiredwithin the boundaries of the selected mask, generating intensity valuesfor Ube3aYFP within each cell.

Human Induced Pluripotent Stem Cell Derived Neurons

GABAergic and glutamatergic induced pluripotent stem cell (iPSC) derivedneural precursor cells (NRC-100-010-001and GNC-301-030-001, CellularDynamics International, Madison Wis.) were differentiated into neuronsaccording to the manufactures protocol. Briefly, neural precursor cellswere thawed and resuspended in chemically defined medium and added tosterile-culture plates coated with poly-D-lysine and laminin. The mediumwas replaced 24 hr after plating and then one-half of the medium wasreplaced every 3-5 days afterwards.

RNA Isolation

For cultured iPSC-derived neurons, RNA isolation and cDNA synthesis wereperformed using the Cell-to-CT kit (Thermo Fisher Scientific) in alysate volume of 55 μl.

Analysis of RNA levels

The steady state RNA levels of target transcripts were measured usingTaqMan quantitative reverse-transcription PCR (qRT-PCR) assays. Totalreaction volume was 10 μL, including 2 μl of cDNA, 1× Gene ExpressionMaster mix (4369016, Thermo Fisher Scientific, Waltham, Mass.), and 1×TaqMan primer assay (Thermo Fisher Scientific). Cycling conditions were2 minutes at 50° C., 10 minutes at 95° C., and 40 cycles of 15 secondsat 95° C. and 1 minute at 60° C., with readings taken at the 60° C. stepof every cycle. Reactions were run on a BIO-RAD T1000 CFX96 thermocycler(Bio-Rad Laboratories, Hercules Calif.), with internal control (PPIA,Hs99999904_m1, Thermo Fisher Scientific) and target [UBE3A-AS,Hs01372957_m1; SNORD116-11, Hs04275268_gH; SNORD115, Hs04275288_gH; IPW,Hs03455409_s1; SNORD109A/B, AP47WVR (Thermo Fisher Scientific); UBE3A:forward ATATGTGGAAGCCGGAATCT (SEQ ID NO:500); reverse:CCCAGAACTCCCTAATCAGAA (SEQ ID NO:501); and, probe: ATGACGGTGGCTATACCAGG(SEQ ID NO:502)] reactions performed together. Data was retrieved andanalyzed with the BIORAD CFX Maestro software (Bio-Rad Laboratories).Samples with internal control Cq values ≥30 were filtered. Quality ofdata was visually inspected to identify discrepancies between technicaland/or plate replicates. Measurements for inferential statistics anddescriptive statistics consist of ΔΔCq values(2^(−ΔΔCq)=2^(−(Cq[target]−Cq[internal control])−(Cq[target]−Cq[internal control]))).

Example 2 Identification of ASO Target Region

Analysis of RNA-sequencing data generated from mouse tissues and cellsrevealed a region located between the 3′-end of the Snord115 cluster and5′-end of the Ube3a antisense (Ube3a-AS) transcript containing geneticelements believed to be important for processing of the Snord115host-gene transcript and transcription of Ube3a-AS (FIGS. 6A-6D).Analysis of RNA-sequencing data generated from human tissues revealed aregion located between the 3′-end of the SNORD115 cluster and SNORD109B(FIGS. 7A-7G) that contained elements similar to those observed inmouse; however, comparative analysis of this region indicated that therewas little to no sequence conservation between human and rodents.

Materials and Methods

RNA-Sequencing

RNA was isolated using Qiagen RNAeasy Plus (74136, Qiagen, Hilden,Germany). RNA concentration was determined using Qubit FluorometricQuantitation (Thermo Fisher Scientific) and RNA quality was assessedusing a 4200 Agilent TapeStation (Agilent, Santa Clara, Calif.).RNA-sequencing libraries were generated using the Illumine TruSeqStranded Total RNA kit (20020597, Illumine, Inc., San Diego, Calif.)according to the manufacturers protocol. 75 base-pair paired-endsequencing was performed using a NextSeq 500 (IIlumina, San Diego,Calif.) at the Texas A&M Institute for Genome Sciences and SocietyGenomics core. Raw sequencing reads were processed using CASAVA. Theresulting FASTQ sequences were examined using FASTQC.

FASTQ sequences were aligned to the human reference assembly (hg19)using Hisat2 (version 2.1.0), with the following settings: —fr. AlignedSAM sequences were then converted to binary BAM sequences, indexed, andsorted using Samtools. BAM files from individual samples were merged andindexed using Samtools. Aligned sequences were filtered using the viewcommand in Samtools to remove non-uniquely aligned reads (quality >1).

A transcript assembly was generated for merged samples using Stringtie(version 1.3.4.d), with the following options: (stranded) —rf -f 0 -j 2.Single exon transcripts were excluded from the assembled transcriptsusing gffread (GFF utilities, Johns Hopkins University, Center forComputational Biology).

Example 3 Identification of Lead ASOs

Eighteen ASOs targeting the ASO-4 and ASO-6.1 target sequences andconsisting of different backbone designs and RNA modifications weredesigned to identify potential lead ASOs (Table 17). Normal iPSCderived-neurons (GABAergic) were treated with a 10-point ½ log doseresponse curve of each ASO to compare the IC₅₀ and E_(max) values.Neural precursor cells were differentiated into neurons for at 18 DIVand then treated with a 10-point ½ log dose response ASOs [1 nM, 3 nM,10 nM, 30 nM, 100 nM, 300 nM, 1 μM, 3 μM, 10 μM, and 30 μM (n=2)]. At 24DIV, the steady state RNA levels of UBE3A-AS were measured and doseresponse curves fitted as described above (FIG. 8A and Table 18). Thedose response curves were significantly different (Parallelism test:F_((51,606))=7.86; p<0.0001; R²=0.90), thus relative potencies were notestimated. Hierarchical clustering of the fitted curves revealed 3Clusters of ASOs, with Cluster 1 representing the 9 most potent ASOs(FIGS. 8B and 8C). Analysis of Cluster 1 indicated that the ASOs hadsimilar curves (Parallelism test: F_((24,299))=1.01; p=0.5; R²=0.93),and that ASO-4.4.PS.L was at least 3-times as potent as the other ASOs(Table 19). Further analysis, however, indicated that ASO-4.4.PS.L,ASO-6.1.PS.M, and ASO-6.1.PO-1.M had equivalent IC₅₀ values, whereas theother ASOs were slightly less potent (Table 20). Based on the relativepotencies and internal selection criteria, ASO-4.4.PS.L andASO-6.1.PO-1.O were investigated further.

TABLE 18 IC₅₀ and E_(max) of Candidate ASOs ASO IC₅₀ (M) IC₅₀ 95% CI (M)E_(max) E_(max) 95% CI 30 μM (Mean) Cluster ASO-4.4.PS.L 2.66E−083.66E−09 1.93E−07 0.0 −0.23 0.23 0.05 1 ASO-6.1.PS.M 1.47E−07 6.80E−083.19E−07 −0.05 −0.21 0.12 0.02 1 ASO-6.1.PO-1.M 1.66E−07 7.15E−083.84E−07 −0.02 −0.20 0.16 0.04 1 ASO-4.4.PO-1.L 2.26E−07 8.95E−085.71E−07 0.04 −0.17 0.25 0.1 1 ASO-4.0.PO-1.M 2.78E−07 1.52E−07 5.08E−070.02 −0.11 0.15 0.05 1 ASO-4.0.PS.M 3.00E−07 1.80E−07 5.00E−07 0.05−0.06 0.15 0.05 1 ASO-6.1. PO-1.O 3.15E−07 7.98E−08 1.24E−06 −0.1 −0.500.26 0.04 1 ASO-6.1.PS.L 3.62E−07 1.37E−07 9.57E−07 −0.07 −0.32 0.180.04 1 ASO-6.1.PS.O 5.32E−07 1.20E−07 2.36E−06 −0.2 −0.67 0.29 0.05 1ASO-6.1.PO-2.L 7.34E−07 5.35E−08 1.01E−05 0.3 −0.11 0.76 0.4 2ASO-4.0.PO-1.O 7.66E−07 3.70E−07 1.59E−06 0.05 −0.12 0.23 0.1 2ASO-4.0.PS.O 1.27E−06 5.13E−07 3.13E−06 0.06 −0.20 0.31 0.1 2ASO-6.1.PO-1.L 1.89E−06 4.42E−07 8.06E−06 0.03 −0.34 0.39 0.2 2ASO-4.0.PO-2.O 1.30E−04 1.65E−17 1.03E+09 −0.3 −9.51 8.94 0.6 2ASO-6.1.PO-2.M 2.69E−04 9.85E−16 7.37E+07 −1.2 −13.16 10.77 0.3 2ASO-4.4.PO-2.L 3.27E+01 0 Inf −2.7 −577 571 0.6 3 ASO-4.0.PO-2.M1.14E+05 0 Inf −76 −74,958. 74,805 0.5 3 ASO-6.1.PO-2.O 1.93E+10 0 Inf−5569 −85,963,650 85,952,510 0.3 3 Full model parameter estimates from4-parameter logistic regression model (Hill). IC50 and confidenceintervals represent molar concentration. Emax and 30 uM values representnormalized UBE3A-AS RNA levels relative to vehicle. Abbreviations: Inf,infinity; 95% CI, 95% confidence intervals

TABLE 19 Relative potency of ASOs in Cluster 1 ASO IC₅₀ (M) RelativePotency Std Error ASO-4.4.PS.L 5.03E−08 1 0 ASO-6.1.PS.M 1.53E−07 0.30.08 ASO-6.1.PO-1.M 1.77E−07 0.3 0.07 ASO-6.1.PO-1.O 1.99E−07 0.3 0.06ASO-4.0.PS.M 2.62E−07 0.2 0.05 ASO-4.0.PO-1.M 2.78E−07 0.2 0.04ASO-6.1.PS.L 2.81E−07 0.2 0.04 ASO-4.4.PO-1.L 3.22E−07 0.2 0.04ASO-6.1.PS.O 4.32E−07 0.1 0.03 Parallel model parameter estimates from 4Parameter logistic regression model (Hill). Abbreviations: M, molar;Std, standard

TABLE 20 Equivalence of ASOs in Cluster 1 Relative to ASO-4.4.PS.L Lowerand Upper IC₅₀ Confidence Limit ASO ASO Ratio Limits ExceededASO-4.4.PS.L ASO-6.1.PO-1.M 0.90 0.81 0.98 Equivalent ASO-6.1.PS.M 0.900.82 0.98 Equivalent ASO-4.0.PO-1.M 0.87 0.79 0.94 Lower ASO-4.0.PS.M0.86 0.79 0.94 Lower ASO-4.4.PO-1.L 0.88 0.79 0.96 Lower ASO-6.1.PO-1.O0.86 0.77 0.95 Lower ASO-6.1.PS.L 0.85 0.77 0.93 Lower ASO-6.1.PS.O 0.830.73 0.92 Lower Two one-sided TestsMaterials and Methods

Methods were similar to those described in Example 2 unless notedotherwise.

Example 4 Pharmacodynamic Analysis of ASO-6A-PO-1.O and ASO-4.4.PS.L inAngelman Syndrome iPSC Neurons

The potencies of ASO-6.1.PS.O and ASO-4.4.PS.L were then examined iniPSC derived-neurons from an Angelman syndrome patient with a maternalderived deletion of the 15q11-q13 region. Induced pluripotent stem cellswere differentiated into neurons and then treated with a 10-point ½ logdose response curve of ASO-6.1.PO-1.O and ASO-4.4.PS.L [1 nM, 3 nM, 10nM, 30 nM, 100 nM, 300 nM, 1 μM, 3 μM, 10 μM, and 30 μM (n=3)]. Six daysfollowing treatment, the steady state RNA levels of UBE3A-AS weremeasured and dose response curves were fitted as described above (FIG.9A). The dose response curves were similar between ASOs (Parallelismtest: F_((3,132))=1.07, p=0.4, R²=0.82), with ASO-4.4.PS.L (437 nM)being approximately 2.7-fold more potent than ASO-6.1.PO-1.O (1.22 uM).The IC₅₀ values were equivalent [ASO-6.1.PO-1.O/ASO-4.4.PS.L IC₅₀ratio:=0.96 (Lower confidence limit=0.9; Upper confidence limit=1.0)].The E_(max) values were similar (30 μM: ASO-4.4.PS.L=0.01±0.0007;ASO-6.1.PO-1.O=0.05±0.004) but not considered equivalent due to theconfidence intervals [A50-6.1.PO-1.O/ASO-4.4.PS.L E_(max) ratio:=−9.1(Lower confidence limit=−224; Upper confidence limit=205)].

Materials and Methods

Methods were similar to those described in Example 2 unless notedotherwise.

Angelman syndrome induced pluripotent stem cells derived neuronsAngelman syndrome iPS cells (AG1-0 iPSCs) (ECN001, Kerafast, Boston,Mass.) were co-cultured on irradiated murine embryonic fibroblasts inhuman embryonic stem cell medium [DMEM/F12 (11330-057, GibcoBiosciences, Dublin, Ireland), 20% Knockout Serum Replacement(10828-028, Thermo Fisher Scientific), 1× Non-essential amino acids, 2mM L-glutamine, 7 μl/mL 2-Mercaptoethanol, and 4 μg/mL basic FibroblastGrowth Factor]. For the first passage, AG1-0 cells were passagedaccording to the product manual for PluriSTEM Human ES/iPS Medium(SCM130, Millipore Sigma, Burlington, Mass.), which is feeder-free andutilizes Dispase II (SCM133, Millipore Sigma) to dissociate cells.Matrigel™ hESC-qualified Matrix (354277, Corning BD Biosciences,Corning, N.Y.) was used as an extracellular matrix. At the secondpassage, the matrix was switched to vitronectin (CC130, MilliporeSigma). During subsequent passages, areas of differentiation weremanually removed until differentiated cells represented approximately<5% of the colonies. After four subsequent passages, AG1-0 cells weredifferentiated using the Millipore ES/iPS Neurogenesis Kit (SCR603,SCM110, and SCM111) but lacking vitronectin as an extracellular matrix.The initial passage was performed with EZ-LiFT (SCM139, Millipore Sigma)to obtain high quality iPS cells. Neural progenitor cells were frozen atstage zero (P₀) and subsequently thawed for differentiation.Differentiation was performed on sterile culture plates coated withpoly-D-lysine (10 μg/mL) and laminin [10 μg/mL (23017-015, Gibco) indifferentiation medium (SCM111) for 10 days of differentiation. In someinstances, cells were differentiated in Cellular Dynamics MaintenanceMedium (NRM-100-121-001, Cellular Dynamics International, Madison,Wis.).

Example 5 Expression Analysis of the PWS Polycistronic Transcript inAngelman Syndrome iPSC Neurons Treated with ASO-6.1-PO-1.O andASO-4.4.PS.L

To determine whether ASO-4.4.PS.L and ASO-6.1.PO-1.O affect the levelsof RNA transcripts encoded by the PWS polycistronic transcript,RNA-sequencing was performed on AS iPS cells treated with each ASO andthe steady state RNA levels of SNURF, SNRPN, the SNORD116 host-genetranscript (SNHG116), the SNORD116 snoRNAs, IPW, the SNORD115 host-genetranscript (SNHG115), the SNORD115 snoRNAs, and UBE3A-AS werequantified. UBE3A steady state RNA levels were also measured. Angelmansyndrome iPS cells were differentiated into neurons as described aboveand then treated with vehicle (1% H₂O, n=3), ASO-4.4.PS.L (30 u μM, n=3)and ASO-6.1.PO-1.O (30 μM, n=3). Six days post-treatment, RNARNA-sequencing was performed on total RNA (rRNA depleted) isolated fromthe cultures. To generate annotations of the SNHG116, SNHG115, andUBE3A-AS transcripts, a transcriptome was assembled from the vehicleRNA-seq data and then incorporated into the reference gene annotation.Relative to vehicle, the steady state RNA levels of SNURF, SNRPN,SNHG116, the SNORD116 snoRNAs, and the SNORD115 snoRNAs were similar andnot significantly different. ASO-4.4.PS.L, but not ASO-6.1.PO-1.O,reduced IPW levels (1.5-fold), but the effect was not significant.ASO-6.1.PO-1.O and ASO-4.4.PS.L significantly reduced SNHG115 andUBE3A-AS RNA levels. ASO-6.1.PO-1.O and ASO-4.4.PS.L had a similareffect on SNHG115 levels; however, ASO-4.4.PS.L had a much larger effecton UBE3A-AS RNA levels than ASO-6.1.PO-1.O (ASO-4.4.PS.L: −6.1-foldchange; ASO-6.1.PO-1.O: −2.8-fold change). ASO treatment increased UBE3ARNA levels by approximately 1.2-fold, but the effect was not significant(FIG. 10 and Table 21).

TABLE 21 Effect of ASO Treatment on RNA Levels of PWS PolycistronicTranscripts and UBE3A Std t Adjusted Gene Treatment Difference ErrorRatio P SNURF ASO-6.1.PO-1.O −0.53 0.51 −1.02 0.5 ASO-4.4.PS.L 0.49 0.510.96 0.6 SNRPN ASO-6.1.PO-1.O 0.03 0.11 0.30 0.9 ASO-4.4.PS.L −0.02 0.11−0.16 1.0 SNHG116 ASO-6.1.PO-1.O −0.07 0.10 −0.75 0.7 ASO-4.4.PS.L −0.240.10 −2.49 0.08 SNORD116 ASO-6.1.PO-1.O −0.04 0.46 −0.08 1.0ASO-4.4.PS.L 0.27 0.45 0.60 0.8 IPW ASO-6.1.PO-1.O 0.18 0.37 0.49 0.8ASO-4.4.PS.L −0.49 0.37 −1.33 0.4 SNH115G ASO-6.1.PO-1.O −0.55 0.09−5.92 0.002 ASO-4.4.PS.L −0.58 0.09 −6.33 0.001 SNORD115 ASO-6.1.PO-1.O0.24 0.52 0.45 0.8 ASO-4.4.PS.L −0.26 0.49 −0.54 0.8 UBE3A-ASASO-6.1.PO-1.O −1.48 0.06 −24.17 <0.0001 ASO-4.4.PS.L −1.94 0.06 −31.56<0.0001 UBE3A ASO-6.1.PO-1.O 0.74 0.48 1.53 0.3 ASO-4.4.PS.L 0.90 0.481.88 0.2 One way ANOVA with Dunnett's multiple comparison test relativeto vehicle.Materials and Methods

Methods were similar to those described in Example 4 unless notedotherwise.

Differential Expression Analysis of PWS RNAs

Normalized FPKM (fragments per thousand per million) values of theRefSeq gene annotation will be estimated using Cuffnorm with the defaultsettings and the following option: -u. The FPKM values of each geneannotation was determined for each sample from the output file and usedfor descriptive and inferential statistics.

Example 6 Pharmacodynamic Analysis of ASO-6.1-PO-1.O and ASO-4.4.PS.L inCynomolgus Macaque

The ASO-4 and ASO-6 target regions are conserved across severalnon-human primate (NHP) species, thus enabling both safety and efficacystudies in a large animal model. To examine the efficacy of ASO-4.4.PS.Land ASO-6.1.PO-1.O in the central nervous system (CNS), ASOs weredelivered to Cynomolgus macaques by intrathecal lumbar puncture. Animalswere administered a single bolus injection of vehicle (0.9% saline,n=5), ASO-6.1.PO-1.O (10 mg, n=3), and ASO.4.4.PS.L (10 mg, n=3).Twenty-eight days following treatment, central nervous (CNS) tissueswere collected and the steady state RNA levels of UBE3A-AS weremeasured. Overall, ASO-4.4.PS.L had a larger effect on UBE3A-AS RNAlevels than ASO-6.1.PO-1.O (Table 22). ASO-4.4.PS.L reduced UBE3A-AS RNAin most CNS regions, with large effects in temporal lobe, primary motorcortex, pons, medulla, hippocampus, globus pallidus, frontal cortex(corona radiata), prefrontal cortex, and lumbar spinal cord. Similarly,ASO-6.1.PO-1.O reduced UBE3A-AS RNA levels in most CNS regions, withlarge effects observed in pons, oculomotor nucleus, and lumbar spinalcord (FIG. 11 and Table 23).

TABLE 22 Effect Size of ASO Treatment on UBE3A-AS RNA Levels in CNS 95%Cohen's Confidence Treatment Treatment* d Intervals FDR VehicleASO-4.4.PS.L 1.4 1.0 1.8 2.3E−10 ASO-6.1.PO-1.O ASO-4.4.PS.L 1.0 0.6 1.56.4E−06 Vehicle ASO-6.1.PO-1.O 0.3 −0.06 0.7 0.09 Students t-test withFDR adjusted P values Cohen's d effect sizes: 0.2, small; 0.5, medium;0.8, large; 1.2, very large Abbreviations: FDR, false discovery rate

TABLE 23 Effect of ASO Treatment on UBE3A-AS RNA Levels in CNS RegionsDiffer- Std t Adjusted CNS Region ASO ence Error Ratio P Caudate NucleusASO-6.1.PO-1.O 0.10 0.22 0.46 0.9 ASO-4.4.PS.L −0.21 0.22 −0.94 0.6Cerebellum ASO-6.1.PO-1.O −0.11 0.09 −1.15 0.5 ASO-4.4.PS.L −0.05 0.09−0.53 0.8 Frontal cortex ASO-6.1.PO-1.O 0.01 0.27 0.04 0.9 ASO-4.4.PS.L−0.71 0.27 −2.66 0.05 Frontal Cortex ASO-6.1.PO-1.O −0.08 0.22 −0.34 0.9(Corona radiata) ASO-4.4.PS.L −0.62 0.22 −2.79 0.04 Globus PallidusASO-6.1.PO-1.O 0.10 0.24 0.40 0.9 ASO-4.4.PS.L −0.38 0.24 −1.54 0.3Hippocampus ASO-6.1.PO-1.O −0.19 0.21 −0.91 0.6 ASO-4.4.PS.L −0.57 0.21−2.66 0.05 Spinal Cord ASO-6.1.PO-1.O −0.32 0.20 −1.63 0.2 (Lumbar)ASO-4.4.PS.L −0.87 0.20 −4.46 0.004 Medulla ASO-6.1.PO-1.O −0.24 0.20−1.16 0.45 ASO-4.4.PS.L −0.32 0.20 −1.59 0.3 Oculomotor ASO-6.1.PO-1.O−0.37 0.29 −1.27 0.4 Nucleus ASO-4.4.PS.L −0.18 0.29 −0.62 0.8 PonsASO-6.1.PO-1.O −0.27 0.21 −1.30 0.4 ASO-4.4.PS.L −0.47 0.21 −2.25 0.1Motor Cortex ASO-6.1.PO-1.O −0.19 0.30 −0.65 0.8 ASO-4.4.PS.L −0.59 0.30−1.99 0.1 Putamen ASO-6.1.PO-1.O 0.07 0.15 0.44 0.9 ASO-4.4.PS.L −0.040.15 −0.25 0.9 Temporal Lobe ASO-6.1.PO-1.O 0.13 0.25 0.54 0.8ASO-4.4.PS.L −0.59 0.25 −2.39 0.08 Thalamus ASO-6.1.PO-1.O −0.02 0.14−0.14 0.9 ASO-4.4.PS.L −0.20 0.14 −1.46 0.3 One way ANOVA with Dunnett'smultiple comparison test relative to vehicle.Materials and MethodsAdministration of ASOs

NHP studies were performed at Northern Biomedical Research and CharlesRiver Laboratories using protocols approved by the institutionsrespective Institutional Animal Care and Use Committees. Male and femaleCynomolgus macaques (Macaca fascicularis) weighing 2-4 kg wereanesthetized and single 1 mL dose of ASO or vehicle was administered viaintrathecal lumbar puncture. The dosing solution was prepared bydissolution of lyophilized ASO in the vehicle control article (0.9%sodium chloride) and was filtered through a 0.2-μm filter. CNS andspinal cord samples were harvested, and the CNS was sectioned into 4-mmcoronal slices. Tissue samples were flash frozen and stored at −80° C.until RNA isolation.

RNA Isolation

A 4 mm tissue punch was taken from each region of interest of whichapproximately half was used for RNA isolation. RNA isolation wasperformed using the Qiagen RNeasy Plus Mini kit (74136, Qiagen) withtissue disruption and lysis performed with 5 mm stainless steel beads ina TissueLyser II. The RNA was eluted in two volumes of 30 μl water, fora total elution volume of 60 μl. RNA was quantified using the Qubit withthe RNA XR assay (Q33224, Thermo Fisher Scientific). cDNA wassynthesized from 2 μg of input RNA using the High Capacity RNA-to-cDNAkit (4387406, Thermo Fisher Scientific) in a total reaction volume of 50μl.

Analysis of UBE3A-AS RNA Levels in Tissues

Cynomolgus macaque UBE3A-AS RNA levels were estimated using SYBR Greenquantitative reverse-transcription PCR (qRT-PCR). Total reaction volumewas 10 μl, including 2 μl of cDNA, 1× PowerUp SYBR Green Master mix(A25741, Thermo Fisher Scientific), and 500 nM of each primer (forwardand reverse). Cycling conditions were 2 minutes at 50° C., 2 minutes at95° C., and 40 cycles of 15 seconds at 95° C. and 1 minute at 60° C.,with readings taken at the 60° C. step of every cycle. Reactions wererun on a BIO-RAD T1000 CFX96 thermocycler, with internal control (PPIA,forward: GTCTCCTTCGAGCTGTTTGC (SEQ ID NO:503); reverse:CCTTTCTCTCCAGTGCTCAGA (SEQ ID NO:504)) and target (UBE3A-AS, forward:CCTGTGAACTTTCAACCAGGA (SEQ ID NO:505); reverse: GGATCAGACTCCAGGCCTTC(SEQ ID NO:506)) reactions performed separately. Data was retrieved andinitial analysis was done with the BIORAD CFX Maestro software, with indepth statistical analyses performed with Excel and JMP.

Example 7 ASOs Targeting Exonic Boundaries of Spliced UBE3A-ASTranscripts

In some embodiments, the target sequence is an exonic boundary involvingUBE3A-AS exons 1-5 and SNORD109B exons 1-2. Target sequences consist of38 nucleotides (19 nucleotides of each exon) centered on the exonicboundary of each exon (19 nucleotides representing the 5′ and 3′-ends ofadjacent exons). There were 12 segments of sequences, with exonicboundaries involving segments 1-2, 2-3, 3-4, 5-6, 7-8, 9-10, and 11-12.The chromosomal coordinates are provided in Table 24. A single mergedjunction sequence was created that shows the spliced exons (|, exonicjunction) and intervening exonic sequences ([]). ASOs (20-, 19, and18-mer) targeting the exonic junctions are provided in Table 25.

Merged Junction-Sequence

(SEQ ID NO: 489)  AATGAAATCTTCTGATTTG|TAAGACATGCTGCCAAGAG[]ATTAGTTTTACACCTTCAG|GATAAAGACTGCTGAGAAG[]GTTTAAGGATGCTATTCTG|AAAAGACTGTGGAGGAAGA[]TTAAGGAAACCATCTCTGG|GATAAGGATGACTGAGGAA[]ATTTAAGGATGCCACTCTG|GTTAAAAGCTGAAACAACT[]GAAACTTCAGGGAAAAGAG|AAGGCCTGGAATCTGATCC. | = 3′-5′ exonicjunction [] = intervening exonic sequence

TABLE 24 Chromosome 15 coordinates of targeted exonic junctions SegmentStart End Exonic Region 1 25,511,743 25,511,761 3′ 2 25,512,05925,512,079 5′ 3 25,512,175 25,512,191 3′ 4 25,513,475 25,513,493 5′ 525,513,582 25,513,600 3′ 6 25,514,752 25,514,770 5′ 7 25,514,86325,514,881 3′ 8 25,516,564 25,516,582 5′ 9 25,516,663 25,516,681 3′ 1025,522,514 25,522,532 5′ 11 25,522,537 25,522,556 3′ 12 25,523,99425,524,012 5′ Human chromosome 15 coordinates (hg19 reference assembly)

TABLE 25 List of Junction ASOs and corresponding target regions ASO sizeTarget Seguence (5′-3′) ASO seguence (5′-3′) 20-mer GAAACCAUCUCUGGGAUAAGSEQ ID NO: 393 CTTATCCCAGAGATGGTTTC SEQ ID NO: 441 AAACCAUCUCUGGGAUAAGGSEQ ID NO: 394 CCTTATCCCAGAGATGGTTT SEQ ID NO: 442 AACCAUCUCUGGGAUAAGGASEQ ID NO: 395 TCCTTATCCCAGAGATGGTT SEQ ID NO: 443 ACCAUCUCUGGGAUAAGGAUSEQ ID NO: 396 ATCCTTATCCCAGAGATGGT SEQ ID NO: 444 CCAUCUCUGGGAUAAGGAUGSEQ ID NO: 397 CATCCTTATCCCAGAGATGG SEQ ID NO: 445 CAUCUCUGGGAUAAGGAUGASEQ ID NO: 398 TCATCCTTATCCCAGAGATG SEQ ID NO: 446 AUCUCUGGGAUAAGGAUGACSEQ ID NO: 399 GTCATCCTTATCCCAGAGAT SEQ ID NO: 447 UCUCUGGGAUAAGGAUGACUSEQ ID NO: 400 AGTCATCCTTATCCCAGAGA SEQ ID NO: 448 CUCUGGGAUAAGGAUGACUGSEQ ID NO: 401 CAGTCATCCTTATCCCAGAG SEQ ID NO: 449 UCUGGGAUAAGGAUGACUGASEQ ID NO: 402 TCAGTCATCCTTATCCCAGA SEQ ID NO: 450 CUGGGAUAAGGAUGACUGAGSEQ ID NO: 403 CTCAGTCATCCTTATCCCAG SEQ ID NO: 451 UGGGAUAAGGAUGACUGAGGSEQ ID NO: 404 CCTCAGTCATCCTTATCCCA SEQ ID NO: 452 GGGAUAAGGAUGACUGAGGASEQ ID NO: 405 TCCTCAGTCATCCTTATCCC SEQ ID NO: 453 GGAUAAGGAUGACUGAGGAASEQ ID NO: 406 TTCCTCAGTCATCCTTATCC SEQ ID NO: 454 GCUGAAACAACUGAAACUUCSEQ ID NO: 407 GAAGTTTCAGTTGTTTCAGC SEQ ID NO: 455 GAAACAACUGAAACUUCAGGSEQ ID NO: 408 CCTGAAGTTTCAGTTGTTTC SEQ ID NO: 456 AAACAACUGAAACUUCAGGGSEQ ID NO: 409 CCCTGAAGTTTCAGTTGTTT SEQ ID NO: 457 AACAACUGAAACUUCAGGGASEQ ID NO: 410 TCCCTGAAGTTTCAGTTGTT SEQ ID NO: 458 ACAACUGAAACUUCAGGGAASEQ ID NO: 411 TTCCCTGAAGTTTCAGTTGT SEQ ID NO: 459 CAACUGAAACUUCAGGGAAASEQ ID NO: 412 TTTCCCTGAAGTTTCAGTTG SEQ ID NO: 460 ACUGAAACUUCAGGGAAAAGSEQ ID NO: 413 CTTTTCCCTGAAGTTTCAGT SEQ ID NO: 461 19-merAACCAUCUCUGGGAUAAGG SEQ ID NO: 414 CCTTATCCCAGAGATGGTT SEQ ID NO: 462ACCAUCUCUGGGAUAAGGA SEQ ID NO: 415 TCCTTATCCCAGAGATGGT SEQ ID NO: 463CCAUCUCUGGGAUAAGGAU SEQ ID NO: 416 ATCCTTATCCCAGAGATGG SEQ ID NO: 464CAUCUCUGGGAUAAGGAUG SEQ ID NO: 417 CATCCTTATCCCAGAGATG SEQ ID NO: 465AUCUCUGGGAUAAGGAUGA SEQ ID NO: 418 TCATCCTTATCCCAGAGAT SEQ ID NO: 466UCUCUGGGAUAAGGAUGAC SEQ ID NO: 419 GTCATCCTTATCCCAGAGA SEQ ID NO: 467CUCUGGGAUAAGGAUGACU SEQ ID NO: 420 AGTCATCCTTATCCCAGAG SEQ ID NO: 468UCUGGGAUAAGGAUGACUG SEQ ID NO: 421 CAGTCATCCTTATCCCAGA SEQ ID NO: 469CUGGGAUAAGGAUGACUGA SEQ ID NO: 422 TCAGTCATCCTTATCCCAG SEQ ID NO: 470UGGGAUAAGGAUGACUGAG SEQ ID NO: 423 CTCAGTCATCCTTATCCCA SEQ ID NO: 471GGGAUAAGGAUGACUGAGG SEQ ID NO: 424 CCTCAGTCATCCTTATCCC SEQ ID NO: 472GGAUAAGGAUGACUGAGGA SEQ ID NO: 425 TCCTCAGTCATCCTTATCC SEQ ID NO: 473AACAACUGAAACUUCAGGG SEQ ID NO: 426 CCCTGAAGTTTCAGTTGTT SEQ ID NO: 474ACAACUGAAACUUCAGGGA SEQ ID NO: 427 TCCCTGAAGTTTCAGTTGT SEQ ID NO: 475CAACUGAAACUUCAGGGAA SEQ ID NO: 428 TTCCCTGAAGTTTCAGTTG SEQ ID NO: 476CAACUGAAACUUCAGGGAA SEQ ID NO: 429 TTCCCTGAAGTTTCAGTTG SEQ ID NO: 47718-mer CCAUCUCUGGGAUAAGGA SEQ ID NO: 430 TCCTTATCCCAGAGATGGSEQ ID NO: 478 CAUCUCUGGGAUAAGGAU SEQ ID NO: 431 ATCCTTATCCCAGAGATGSEQ ID NO: 479 AUCUCUGGGAUAAGGAUG SEQ ID NO: 432 CATCCTTATCCCAGAGATSEQ ID NO: 480 UCUCUGGGAUAAGGAUGA SEQ ID NO: 433 TCATCCTTATCCCAGAGASEQ ID NO: 481 CUCUGGGAUAAGGAUGAC SEQ ID NO: 434 GTCATCCTTATCCCAGAGSEQ ID NO: 482 UCUGGGAUAAGGAUGACU SEQ ID NO: 435 AGTCATCCTTATCCCAGASEQ ID NO: 483 CUGGGAUAAGGAUGACUG SEQ ID NO: 436 CAGTCATCCTTATCCCAGSEQ ID NO: 484 UGGGAUAAGGAUGACUGA SEQ ID NO: 437 TCAGTCATCCTTATCCCASEQ ID NO: 485 GGGAUAAGGAUGACUGAG SEQ ID NO: 438 CTCAGTCATCCTTATCCCSEQ ID NO: 486 GGAUAAGGAUGACUGAGG SEQ ID NO: 439 CCTCAGTCATCCTTATCCSEQ ID NO: 487 ACAACUGAAACUUCAGGG SEQ ID NO: 440 CCCTGAAGTTTCAGTTGTSEQ ID NO: 488

Example 8 siRNA, shRNA, and CRISPR Guide RNAs Targeting UBE3a-AS Exons1-5

As noted above, in some embodiments, the disclosed oligonucleotide is afunctional nucleic acid, such as a siRNA, shRNA, or nuclease gRNA, thatinhibits, mutates, or deletes the target nucleic acid sequence.

Examples of siRNA targeting UBE3a-AS exons 1-5 are provided in Table 26.Examples of shRNA targeting UBE3a-AS exons 1-5 are provided in Table 27.Examples of gRNA targeting UBE3a-AS exons 1-5 are provided in Table 28.

TABLE 26 siRNA targeting UBE3a-AS exons 1-5 Target seguence SiRNACCCAGGUGUCCUUUAAUGAA SEQ ID NO: 507 TTCATTAAAGGACACCTGGG SEQ ID NO: 538CCAGGUGUCCUUUAAUGAAA SEQ ID NO: 508 TTTCATTAAAGGACACCTGG SEQ ID NO: 539UGAAAAUGCUCUUGACACCA SEQ ID NO: 509 TGGTGTCAAGAGCATTTTCA SEQ ID NO: 540GAAAAUGCUCUUGACACCAA SEQ ID NO: 510 TTGGTGTCAAGAGCATTTTC SEQ ID NO: 541AAAUGCUCUUGACACCAAUG SEQ ID NO: 511 CATTGGTGTCAAGAGCATTT SEQ ID NO: 542AGAUCAGUAGCUUCCUUUAC SEQ ID NO: 512 GTAAAGGAAGCTACTGATCT SEQ ID NO: 543UCAGUAGCUUCCUUUACCGA SEQ ID NO: 513 TCGGTAAAGGAAGCTACTGA SEQ ID NO: 544UCUAGAACAUUGAGCUAUGG SEQ ID NO: 514 CCATAGCTCAATGTTCTAGA SEQ ID NO: 545CUAGAACAUUGAGCUAUGGA SEQ ID NO: 515 TCCATAGCTCAATGTTCTAG SEQ ID NO: 546AACAUUGAGCUAUGGAAGAC SEQ ID NO: 516 GTCTTCCATAGCTCAATGTT SEQ ID NO: 547ACAUUGAGCUAUGGAAGACU SEQ ID NO: 517 AGTCTTCCATAGCTCAATGT SEQ ID NO: 548CUAUGGAAGACUCCCACCUA SEQ ID NO: 518 TAGGTGGGAGTCTTCCATAG SEQ ID NO: 549UAUGGAAGACUCCCACCUAA SEQ ID NO: 519 TTAGGTGGGAGTCTTCCATA SEQ ID NO: 550CAAGUGCUACCGCACAGGCA SEQ ID NO: 520 TGCCTGTGCGGTAGCACTTG SEQ ID NO: 551AAGUGCUACCGCACAGGCAU SEQ ID NO: 521 ATGCCTGTGCGGTAGCACTT SEQ ID NO: 552UACCGCACAGGCAUGCUGCA SEQ ID NO: 522 TGCAGCATGCCTGTGCGGTA SEQ ID NO: 553CAGGCAUGCUGCAGUGAAUU SEQ ID NO: 523 AATTCACTGCAGCATGCCTG SEQ ID NO: 554AGGCAUGCUGCAGUGAAUUU SEQ ID NO: 524 AAATTCACTGCAGCATGCCT SEQ ID NO: 555ACCGUUGUUUAAGGAUGCUA SEQ ID NO: 525 TAGCATCCTTAAACAACGGT SEQ ID NO: 556CCGUUGUUUAAGGAUGCUAU SEQ ID NO: 526 ATAGCATCCTTAAACAACGG SEQ ID NO: 557CUGUGGAGGAAGAAAACCCU SEQ ID NO: 527 AGGGTTTTCTTCCTCCACAG SEQ ID NO: 558AAGAAAACCCUUUACCCUGU SEQ ID NO: 528 ACAGGGTAAAGGGTTTTCTT SEQ ID NO: 559AGAAAACCCUUUACCCUGUU SEQ ID NO: 529 AACAGGGTAAAGGGTTTTCT SEQ ID NO: 560CUCAACUGCCUGGCACUGAA SEQ ID NO: 530 TTCAGTGCCAGGCAGTTGAG SEQ ID NO: 561AACUGCCUGGCACUGAAAAU SEQ ID NO: 531 ATTTTCAGTGCCAGGCAGTT SEQ ID NO: 562ACUGCCUGGCACUGAAAAUG SEQ ID NO: 532 CATTTTCAGTGCCAGGCAGT SEQ ID NO: 563GUGUUUAAGGAAACCAUCUC SEQ ID NO: 533 GAGATGGTTTCCTTAAACAC SEQ ID NO: 564GUUUAAGGAAACCAUCUCUG SEQ ID NO: 534 CAGAGATGGTTTCCTTAAAC SEQ ID NO: 565AGGAAACCAUCUCUGAUAAG SEQ ID NO: 535 CTTATCAGAGATGGTTTCCT SEQ ID NO: 566UCUUUGGCUUGUUGACACCA SEQ ID NO: 536 TGGTGTCAACAAGCCAAAGA SEQ ID NO: 567CUUUGGCUUGUUGACACCAG SEQ ID NO: 537 CTGGTGTCAACAAGCCAAAG SEQ ID NO: 568

TABLE 27 shRNA targeting UBE3a-AS exons 1-5GGTGCCATTCTATTATAAAtaacctgacccattaTTTATAATAGAATGGCACCTTTTTSEQ ID NO: 569GCTTTCATCAATAATGAAAtaacctgacccattaTTTCATTATTGATGAAAGCTTTTTSEQ ID NO: 570GGTCTTTCATCAATAATGAtaacctgacccattaTCATTATTGATGAAAGACCTTTTTSEQ ID NO: 571GAAATCTTCTGATTTGTAAtaacctgacccattaTTACAAATCAGAAGATTTCTTTTTSEQ ID NO: 572GCACCTAAGGGAATTAGTAtaacctgacccattaTACTAATTCCCTTAGGTGCTTTTTSEQ ID NO: 573GTTTCAACCAGGATTTAAAtaacctgacccattaTTTAAATCCTGGTTGAAACTTTTTSEQ ID NO: 574GCTTTCAACCAGGATTTAAtaacctgacccattaTTAAATCCTGGTTGAAAGCTTTTTSEQ ID NO: 575GGAGATGTGCCATTCTATAtaacctgacccattaTATAGAATGGCACATCTCCTTTTTSEQ ID NO: 576GTCTTTCATCAATAATGAAtaacctgacccattaTTCATTATTGATGAAAGACTTTTTSEQ ID NO: 577GATCAATAATGAAATCTTAtaacctgacccattaTAAGATTTCATTATTGATCTTTTTSEQ ID NO: 578GTGTCTTTCATCAATAATAtaacctgacccattaTATTATTGATGAAAGACACTTTTTSEQ ID NO: 579GCAATAATGAAATCTTCTAtaacctgacccattaTAGAAGATTTCATTATTGCTTTTTSEQ ID NO: 580GCATGCTGCAGTGAATTTAtaacctgacccattaTAAATTCACTGCAGCATGCTTTTTSEQ ID NO: 581GGAAATCTTCTGATTTGTAtaacctgacccattaTACAAATCAGAAGATTTCCTTTTTSEQ ID NO: 582GGTATATTCTATCTAGAAAtaacctgacccattaTTTCTAGATAGAATATACCTTTTTSEQ ID NO: 583GTGCTGCAGTGAATTTAAAtaacctgacccattaTTTAAATTCACTGCAGCACTTTTTSEQ ID NO: 584GTGTGCCATTCTATTATAAtaacctgacccattaTTATAATAGAATGGCACACTTTTTSEQ ID NO: 585GTTACCATCAGTGTTTAAAtaacctgacccattaTTTAAACACTGATGGTAACTTTTTSEQ ID NO: 586GCCTGCAACCGTTGTTTAAtaacctgacccattaTTAAACAACGGTTGCAGGCTTTTTSEQ ID NO: 587GTATGTCTTTCATCAATAAtaacctgacccattaTTATTGATGAAAGACATACTTTTTSEQ ID NO: 588

TABLE 28 CRISPR Guide RNAs targeting UBE3a-AS exons 1-5 Strand SeguenceSEQ ID PAM - ACACTGATGGTAAAGTGGAC SEQ ID NO: 589 TGG -TAGAATATACACGTCGGTAA SEQ ID NO: 590 AGG - TCAACTGTCCCAGTCACAACSEQ ID NO: 591 AGG - TCTAGATAGAATATACACGT SEQ ID NO: 592 CGG -TCTAGATAGAATATACACGT SEQ ID NO: 593 CGG - CTCCCCATGCACACTTGAGASEQ ID NO: 594 AGG - CATCCTTAAACAACGGTTGC SEQ ID NO: 595 AGG -GGTGTAAAACTAATTCCCTT SEQ ID NO: 596 AGG - AACAACGGTTGCAGGGACAGSEQ ID NO: 597 AGG + TATGGAAGACTCCCACCTAA SEQ ID NO: 598 GGG +CTATGGAAGACTCCCACCTA SEQ ID NO: 599 AGG + AAGCCTTCTCAAGTGTGCATSEQ ID NO: 600 GGG + CTATCTAGAACATTGAGCTA SEQ ID NO: 601 TGG +ACCCTCTGGTGTTGTCACAG SEQ ID NO: 602 AGG + AACCCTTTACCCTGTTGTTCSEQ ID NO: 603 AGG

Unless defined otherwise, all technical and scientific terms used hereinhave the same meanings as commonly understood by one of skill in the artto which the disclosed invention belongs. Publications cited herein andthe materials for which they are cited are specifically incorporated byreference.

Those skilled in the art will recognize, or be able to ascertain usingno more than routine experimentation, many equivalents to the specificembodiments of the invention described herein. Such equivalents areintended to be encompassed by the following claims.

What is claimed is:
 1. A method for treating or preventing Angelmansyndrome in a subject suffering from or susceptible to Angelmansyndrome, the method comprising administering a therapeutically orprophylactically effective amount of a pharmaceutical compositioncomprising one or more antisense oligonucleotide (ASO) to the subject,wherein the one or more ASO consists of a contiguous nucleotide sequenceof 10 to 30 nucleotides in length with nucleic acid sequencecomplementarity to a contiguous portion of the nucleotide sequence setforth in SEQ ID NO: 2, and wherein the one or more ASO comprises one ormore modified nucleoside.
 2. The method of claim 1, wherein the one ormore ASO comprises a sequence having 100% nucleic acid sequencecomplementarity to a nucleotide sequence selected from the groupconsisting of SEQ ID NOs: 18 to
 66. 3. The method of claim 1, whereinthe one or more ASO comprises a nucleotide sequence selected from thegroup consisting of SEQ ID NO: 87, SEQ ID NO: 88, SEQ ID NO: 89, SEQ IDNO: 90, and SEQ ID NO:
 91. 4. The method of claim 3, wherein the one ormore ASO comprises the nucleotide sequence set forth in SEQ ID NO: 89.5. The method of claim 1, wherein the one or more modified nucleosidecomprises a 2′ sugar modified nucleoside.
 6. The method of claim 5,wherein the one or more 2′ sugar modified nucleoside is independentlyselected from the group consisting of 2-O-alkyl-RNA, 2′-O-methyl-RNA,2′-alkoxy-RNA, 2-O-methoxyethyl-RNA, 2′-amino-DNA, 2′-fluoro-DNA,arabino nucleic acid (ANA), 2-fluoro-ANA, and locked nucleic acid (LNA)nucleoside.
 7. The method of claim 6, wherein the one or more modifiednucleoside comprises a LNA nucleoside.
 8. The method of claim 1, whereinthe one or more modified nucleoside comprises a ribonucleotidesubstitution.
 9. The method of claim 8, wherein the one or more ASOcomprises a gapmer.
 10. The method of claim 9, wherein the gapmercomprises a sequence selected from the group consisting of SEQ ID NOs:365 and 371-383.
 11. The method of claim 1, wherein the one or more ASOcomprises at least one modified internucleoside linkage.
 12. The methodof claim 11, wherein the at least one modified internucleoside linkagecomprises a phosphorothioate internucleoside linkage.
 13. The method ofclaim 12, wherein the one or more ASO is fullyphosphorothioate-modified.